Quantum information, quantum matter and quantum gravity |  Kyoto | 27.09.2023

Extreme Value Theory

And

LocalIZation IN RANDOM spin chains

Jeanne Colbois

Nicolas Laflorencie

LPT | CNRS & Toulouse University | France

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Tossing a coin

1

image/svg+xml

M. F. Schilling, The College Mathematics Journal 21(3), 196-207 (1990)

P. Révész, Proc. 1978 Int'l Cong. of Mathematicians, 749-754 (1980)

\(L = 176 \)

HTTHTHH
THTHHT

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Tossing a coin

2

HTTHTHTTHTHHHTHTTHHTTHHTHTTTHHHTTHTHTHTHHTHTHTHTHTHHTHTHHTHTHTHHTHTHTHHTHTHTTHTHTHTHHHTHTHTHTTHHTHTHTHTHHTHHHTTTHHTHTHTHTHTHTHHTHTHTHHTHTHHTTHTHHTHTHTHHTHTHHTHTHTHTHTHHTHTHHTHT

176 (81 T / 95 H )

HTTTHTTTHTHTHHTHHHHHHTTTTHHHHHHHTHTHHHTTHTHHTHHTTTHHHTHHHTTHHHHTHHTHHHTTTHTHTTHTHTTHHTHTTHTHTTTTTTTHHTHTHHHTHHTTHHTTTTTHHHTTHTHTHHTHTTHTTHHHHTHTHHHTTTTTHTHTTHHTHTTHHTHHHHTHHTHT

176 (83 T / 93 H )

M. F. Schilling, The College Mathematics Journal 21(3), 196-207 (1990)

P. Révész, Proc. 1978 Int'l Cong. of Mathematicians, 749-754 (1980)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Tossing a coin

HTTHTHTTHTHHHTHTTHHTTHHTHTTTHHHTTHTHTHTHHTHTHTHTHTHHTHTHHTHTHTHHTHTHTHHTHTHTTHTHTHTHHHTHTHTHTTHHTHTHTHTHHTHHHTTTHHTHTHTHTHTHTHHTHTHTHHTHTHHTTHTHHTHTHTHHTHTHHTHTHTHTHTHHTHTHHTHT

176 (81 T / 95 H )

HTTTHTTTHTHTHHTHHHHHHTTTTHHHHHHHTHTHHHTTHTHHTHHTTTHHHTHHHTTHHHHTHHTHHHTTTHTHTTHTHTTHHTHTTHTHTTTTTTTHHTHTHHHTHHTTHHTTTTTHHHTTHTHTHHTHTTHTTHHHHTHTHHHTTTTTHTHTTHHTHTTHHTHHHHTHHTHT

176 (83 T / 93 H )

M. F. Schilling, The College Mathematics Journal 21(3), 196-207 (1990)

P. Révész, Proc. 1978 Int'l Cong. of Mathematicians, 749-754 (1980)

image/svg+xml
\mathcal{P}(\ell) \sim 2^{-\ell}
\mathcal{P}(\ell_{\max}) \sim \frac{1}{L}
\Rightarrow \ell_{\max} \sim \ln L / \ln 2 \sim 7.45

2

Extreme value theory

Athletic records

Market risks

Extreme floods

Large wildfires

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

3

Extreme value theory

Athletic records

Market risks

Extreme floods

Large wildfires

Condensed matter

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

3

Extreme value theory

Disordered spin chains

Athletic records

Market risks

Extreme floods

Large wildfires

Condensed matter

R. Juhász, Y,C. Lin, and F, Iglói, Phys. Rev. B 73, 224206 (2006)

N. Pancotti, M. Knap, D. A. Huse, J. I. Cirac, and M. C. Bañuls, Phys. Rev. B 97, 094206 (2018)

I. A. Kovács, T.Pető, and F.Iglói, Phys. Rev. Res. 3, 033140 (2021)

W.-H. Kao and N, B. Perkins,  Phys. Rev. B 106, L100402 (2022)

J. C., N. Laflorencie, arXiv:2305.10574

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

3

Summary : Spin-1/2 chain in random field

4

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Spin-1/2            \(W = h = \) disorder strength for random fields along \(S^z\)

4

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Spin-1/2            \(W = h = \) disorder strength for random fields along \(S^z\)

Heisenberg chain

XX chain ("many-body Anderson")

Summary : Spin-1/2 chain in random field

4

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Spin-1/2            \(W = h = \) disorder strength for random fields along \(S^z\)

E_m

Eigenstates in the middle of the many-body spectrum

Heisenberg chain

XX chain ("many-body Anderson")

Summary : Spin-1/2 chain in random field

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distribution over disorder realizations and high-energy eigenstates

5

Anderson chain / XX chain

Summary : Spin-1/2 chain in random field

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distribution over disorder realizations and high-energy eigenstates

5

Anderson chain / XX chain

Summary : Spin-1/2 chain in random field

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distribution over disorder realizations and high-energy eigenstates

5

Anderson chain / XX chain

Heisenberg chain

Summary : Spin-1/2 chain in random field

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distribution over disorder realizations and high-energy eigenstates

5

Anderson chain / XX chain

Heisenberg chain

Summary : Spin-1/2 chain in random field

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distribution over disorder realizations and high-energy eigenstates

5

Anderson chain / XX chain

Heisenberg chain

Summary : Spin-1/2 chain in random field

QUestions

Spin-1/2    \(W = h = \) disorder strength for random fields

6

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

W

Ergodic

MBL regime(s)

Spin-1/2    \(W = h = \) disorder strength for random fields

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

6

W

Ergodic

MBL regime(s)

Fate of isolated

quantum systems?

QUestions

Spin-1/2    \(W = h = \) disorder strength for random fields

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

  • Toy model?

6

W

Ergodic

MBL regime(s)

QUestions

Spin-1/2    \(W = h = \) disorder strength for random fields

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

 

  • Quantitative description?
  • Toy model?

6

W

Ergodic

MBL regime(s)

QUestions

Spin-1/2    \(W = h = \) disorder strength for random fields

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

  • Toy model?

 

  • Quantitative description?
  • Consequences?

6

W

Ergodic

MBL regime(s)

QUestions

Scope

1. Spin chains in random field and localization : introduction

2. Exact diagonalization

4. Quantitative analysis: extreme value theory

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

3. Minimal deviations in the XX chain

5. Consequences

Spin chains in Random field and localization

Spin-1/2 chain in a random field 

7

\mathcal{H} = \sum_{i} \frac{J}{2}\left(S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+} + 2\Delta S_i^z S_{i+1}^z\right) - \sum_{i} h_i S_i^z
S^{x,y,z} = \frac{1}{2} \sigma^{x,y,z}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Spin-1/2 chain in a random field 

S^{x,y,z} = \frac{1}{2} \sigma^{x,y,z}
\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left(c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}+2 \Delta n_i n_{i+1} \right) -h_i n_i\Bigr]

Jordan-Wigner

Spinless fermions

(hardcore bosons)

P. Jordan and E. Wigner,  Z. Physik 47, 631–651 (1928)

\mathcal{H} = \sum_{i} \frac{J}{2}\left(S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+} + 2\Delta S_i^z S_{i+1}^z\right) - \sum_{i} h_i S_i^z

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

7

Spin-1/2 chain in a random field 

S^{x,y,z} = \frac{1}{2} \sigma^{x,y,z}

Jump

Magnetic field

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}
\mathcal{P}(h_i) =

Spin-flip

On-site energy

\(-W\)

\(W\)

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

Attraction/ repulsion

Attraction/ repulsion

Ising interaction

P. Jordan and E. Wigner,  Z. Physik 47, 631–651 (1928)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

7

Anderson Localization

8

1 particle

Magnetic field

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

Spin-flip

Ising interaction

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

Anderson Localization

1 particle

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

9

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

Anderson Localization

1 particle

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{m} \epsilon_m b_m^{\dagger}b_m

9

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

\epsilon_m

Anderson Localization

1 particle

{\xi}(E, {\color{#76a5af}W})
\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

\epsilon_m

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{m} \epsilon_m b_m^{\dagger}b_m

9

Localization length

{\xi}(E, {\color{#76a5af}W})

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

10

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

\(\epsilon\)

\(\xi(\epsilon, W)\)

Localization length

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

\(\epsilon\)

\(\xi(\epsilon, W)\)

{\xi}(E, {\color{#76a5af}W})

10

Localization length

{\xi}(E, {\color{#76a5af}W})

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

\(\epsilon\)

\(\xi(\epsilon, W)\)

10

Localization length

{\xi}(E, {\color{#76a5af}W})
\xi = \frac{1}{\ln\left(1+\left(\frac{W}{W_0}\right)^2 \right)}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\(\epsilon\)

\(\xi(\epsilon, W)\)

\xi \ll 1
W \gg 2

10

A. C. Potter, R. Vasseur, and S. A. Parameswaran, PRX 5, 031033 (2015)

P. W. Anderson, Phys. Rev. 109, 1492 (1958); N.F. Mott & W.D. Twose,  Advances in Physics 10, 107-163, (1961) 

B. A. Van Tiggelen, In: J. P. Fouque (eds), Diffuse Waves in Complex Media, NATO Science Series, 531, Springer, Dordrecht, (1999)

"Many-Body" Anderson Insulator (= XX chain)

\(L/2\) fermions

\(S_z = 0\)

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\epsilon_m

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

12

\(L/2\) fermions

\(S_z = 0\)

|\Psi \rangle = | \left\{\phi_m, m \in {\color{#56B4E9}\mathrm{occ}} \right\}\rangle
\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\epsilon_m
E_m

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

"Many-Body" Anderson Insulator (= XX chain)

12

Heisenberg: Introducing interactions

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

13

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}
\mathcal{H} = \sum_m \epsilon_m b_m^{\dagger} b_m + \sum_{j,k,l,m} {\color{#ff9900}V_{j,k,l,m} b_j^{\dagger} b_k^{\dagger} b_l b_m}

In the Anderson basis: 

Anderson 

orbitals \(m\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

14

P. W. Anderson, Phys. Rev. 109, 1492 (1958)

Effect of interactions?

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}
\mathcal{H} = \sum_m \epsilon_m b_m^{\dagger} b_m + \sum_{j,k,l,m} {\color{#ff9900}V_{j,k,l,m} b_j^{\dagger} b_k^{\dagger} b_l b_m}

In the Anderson basis: 

Anderson 

orbitals \(m\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

14

P. W. Anderson, Phys. Rev. 109, 1492 (1958)

Effect of interactions?

Interactions favor delocalization. Do they fully destroy localization?

Effect of interactions? GRound state 

15

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

Do interactions destroy localization?

Effect of interactions? GRound state 

15

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

Do interactions destroy localization?

T. Giamarchi and H. J. Schulz, EPL 3 1287 (1987); PRB 37, 325 (1988)

Z. Ristivojevic, et al PRL 109, 026402 (2012);

Doggen et al, PRB 96, 180202(R) (2017)

Effect of interactions?

16

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

Do interactions destroy localization?

What about high temperatures / high energy eigenstates?

T. Giamarchi and H. J. Schulz, EPL 3 1287 (1987); PRB 37, 325 (1988)

Z. Ristivojevic, et al PRL 109, 026402 (2012);

Doggen et al, PRB 96, 180202(R) (2017)

Effect of interactions? 

16

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

Do interactions destroy localization?

T. Giamarchi and H. J. Schulz, EPL 3 1287 (1987); PRB 37, 325 (1988)

Z. Ristivojevic, et al PRL 109, 026402 (2012);

Doggen et al, PRB 96, 180202(R) (2017)

What about high temperatures / high energy eigenstates?

J. M. Deutsch , PRA. 43, 2046–2049, (1991) ,

M. Srednicki, PRE 50,  888–901, (1994)

L. D’Alessio, Y. Kafri, A. Polkovnikov, and M. Rigol, Adv. Phys. 65, 239 (2016)

Do isolated quantum systems thermalize?

Thermal average 

?

ETH

Time average

Weak interactions and disorder

17

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Analytical, general picture:

 

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

L. Fleischman, P. W. Anderson, PRB 2, 2336 (1980) \(\rightarrow\) single-particle excitations and conditions for Anderson transition

B. Altschuler, Y. Gefen, A. Kamenev, L. S. Levitov, PRL 78,  2803, (1997) \(\rightarrow\) quasi particle lifetime & localization in Fock space

P. Jacquod, D. L. Shepelyansky, PRL 79, 1837 (1997) \(\rightarrow\) Gap ratio statistics, finite systems

I. V. Gornyi, A. D. Mirlin, D. G. Polyakov, PRL 95, 206603 (2005) \(\rightarrow\) zero  conductivity at low temperature

*D. M. Basko, I. L. Aleiner, B. L. Altschuler, Annals of Physics 321, 1126 (2006) \(\rightarrow\) metal-insulator transition, localization in Fock space

I.L. Aleiner, B. L. Altshuler, G. V Shlyapnikov, Nature Physics 6, 900-904 (2010) \(\rightarrow\) weakly interacting bosons

Weak interactions and disorder

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Analytical, general picture:

Interactions \(\Rightarrow\) transition between weak and strong disorder

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

disorder

interactions

Anderson localized

Delocalized

Ergodic

Insulator

L. Fleischman, P. W. Anderson, PRB 2, 2336 (1980) \(\rightarrow\) single-particle excitations and conditions for Anderson transition

B. Altschuler, Y. Gefen, A. Kamenev, L. S. Levitov, PRL 78,  2803, (1997) \(\rightarrow\) quasi particle lifetime & localization in Fock space

P. Jacquod, D. L. Shepelyansky, PRL 79, 1837 (1997) \(\rightarrow\) Gap ratio statistics, finite systems

I. V. Gornyi, A. D. Mirlin, D. G. Polyakov, PRL 95, 206603 (2005) \(\rightarrow\) zero  conductivity at low temperature

*D. M. Basko, I. L. Aleiner, B. L. Altschuler, Annals of Physics 321, 1126 (2006) \(\rightarrow\) metal-insulator transition, localization in Fock space

I.L. Aleiner, B. L. Altshuler, G. V Shlyapnikov, Nature Physics 6, 900-904 (2010) \(\rightarrow\) weakly interacting bosons

17

18

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

A. Pal, D. Huse, PRB 82, 174411 2010

(See series of works by V. Oganesyan, A. Pal, D. Huse, 2007-2010)

Exact diagonalization

disorder

gap ratio

Probes: gap ratio 

18

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

Gaussian orthogonal ensemble statistics = random matrix

level repulsion

\(\leftrightarrow\) ergodic

A. Pal, D. Huse, PRB 82, 174411 2010

(See series of works by V. Oganesyan, A. Pal, D. Huse, 2007-2010)

Exact diagonalization

disorder

gap ratio

Probes: gap ratio 

18

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

Gaussian orthogonal ensemble statistics = random matrix

level repulsion

\(\leftrightarrow\) ergodic

Poisson statistics 

non-ergodic

A. Pal, D. Huse, PRB 82, 174411 2010

(See series of works by V. Oganesyan, A. Pal, D. Huse, 2007-2010)

Exact diagonalization

disorder

gap ratio

Probes: gap ratio 

19

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

Probes: gap ratio  |  entanglement entropy 

Initial \(S^z\) basis random product state

+

TEBD

 

W = 5

Anderson

No growth

of entanglement

J. H. Bardarson, F. Pollmann, and J. E. Moore, PRL 109, 017202 (2012)

M. Znidaric, T. Prosen, and P. Prelovsek PRB 77, 064426 (2008)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

Probes: gap ratio  |  entanglement entropy 

Anderson

No growth

of entanglement

J. H. Bardarson, F. Pollmann, and J. E. Moore, PRL 109, 017202 (2012)

M. Znidaric, T. Prosen, and P. Prelovsek PRB 77, 064426 (2008)

Many body

Log growth

of entanglement

19

Initial \(S^z\) basis random product state

+

TEBD

 

W = 5

20

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

\(\frac{E -E_{\min}}{E_{\max}-E_{\min}}\)

D. J. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015) 

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

Probes: gap ratio  |  entanglement entropy  |  participation entropy 

|\Psi\rangle = \sum_{\alpha = 1}^{\mathcal{N}} \psi_{\alpha} |\alpha \rangle
S_q = \frac{1}{1-q} \ln\left(\sum_{\alpha=1}^{\mathcal{N}} |\psi_{\alpha}|^{2q}\right)

Configuration space

S_q = a_q \ln(\mathcal{N})

20

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Heisenberg in random field : A paradigmatic example

\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

A few among many...

D. A. Abanin, E. Altman, I. Bloch, and M. Serbyn, Rev. Mod. Phys. 91, 021001 (2019)            F. Alet, N. Laflorencie, C. R. Phys. 19,498 (2018)

Probes: gap ratio  |  entanglement entropy  |  participation entropy  | imbalance [...]

M. Schreiber et al. (I. Bloch) , Science 349, 842 (2015) 

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

W

Ergodic

MBL 

2016

Finite L

debate

21

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

W

Ergodic

MBL 

2016

Finite L

  • Finite-size scaling? Location of the transition?
  • Destabilization by ergodic bubbles even at strong disorder?
  • Immediate onset of quantum chaos? Intermediate phase(s)?

debate

21

W

Ergodic

MBL phase/ regimes?

Prethermal

regime?

2023

J. Šuntajs, J. Bonča, T. Prosen, and L. Vidmar, PRE 102, 062144 (2020); D.A. Abanin, et al, Annals of Physics 427, 168415, (2021); 

D. Sels, A. Polkovnikov, JCCM January 2023_1 (2023); Tyler LeBlond, Dries Sels, Anatoli Polkovnikov, and Marcos Rigol, PRB 104, L201117 (2021);  A. Morningstar et al, PRB 105, 174205 (2022); L. Colmenarez, D. Luitz, W. De Roeck, arXiv:2308.01350 (2023); P, Sierant and J. Zakrzewski, PRB 105, 224203 (2022)...

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

W

Ergodic

MBL 

2016

Finite L

  • Finite-size scaling? Location of the transition?
  • Destabilization by ergodic bubbles even at strong disorder?
  • Immediate onset of quantum chaos? Intermediate phase(s)?

debate

21

W

Ergodic

MBL phase/ regimes?

Prethermal

regime?

For today :  Magnetization, ED data and comparison to the Anderson line

J. Šuntajs, J. Bonča, T. Prosen, and L. Vidmar, PRE 102, 062144 (2020); D.A. Abanin, et al, Annals of Physics 427, 168415, (2021); 

D. Sels, A. Polkovnikov, JCCM January 2023_1 (2023); Tyler LeBlond, Dries Sels, Anatoli Polkovnikov, and Marcos Rigol, PRB 104, L201117 (2021);  A. Morningstar et al, PRB 105, 174205 (2022); L. Colmenarez, D. Luitz, W. De Roeck, arXiv:2308.01350 (2023); P, Sierant and J. Zakrzewski, PRB 105, 224203 (2022)...

2023

Exact diagonalization

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

challenge

22

 

  • Many-body                                            

 

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

Simulations of Many-Body Localizable (MBL) lattices models | Fabien Alet | Cargese

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

challenge

 

  • Many-body                                            

 

  • Disorder \(\rightarrow\) translation invariance, high number of realisations

 

 

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

22

Simulations of Many-Body Localizable (MBL) lattices models | Fabien Alet | Cargese

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

challenge

22

 

  • Many-body                                            

 

  • Disorder \(\rightarrow\) translation invariance, high number of realisations

 

  • High-energy eigenstates 

 

  • High density of eigenstates

 

  • Potential absence of thermalization

 

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

Simulations of Many-Body Localizable (MBL) lattices models | Fabien Alet | Cargese

23

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

Idea : transform the spectrum!

F = (H - \sigma)^2

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

23

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

Idea : transform the spectrum!

F = (H - \sigma)^2

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

23

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

Idea : transform the spectrum!

F = (H - \sigma)^2
G = (H - \sigma)^{-1}

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

23

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

Idea : transform the spectrum!

F = (H - \sigma)^2
G = (H - \sigma)^{-1}
 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

Do not invert!

Solve \((H-\sigma) \vec{y} = \vec{x}\)

23

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

Idea : transform the spectrum!

F = (H - \sigma)^2
G = (H - \sigma)^{-1}
G = "\sum_k \alpha_k H^k"

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

23

spectral transformation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{N} = \frac{L!}{\left(\frac{L}{2}!\right)^2}

High energy eigenstates close to \(\epsilon = \sigma\), high dos

Idea : transform the spectrum!

F = (H - \sigma)^2
G = (H - \sigma)^{-1}
G = "\sum_k \alpha_k H^k"

\(L = 14, S^z_{\mathrm{tot}} = 0\), clean case

 

D. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015)

F. Pietracaprina, et al, .SciPost Phys. 5, 045 (2018)

P. Sierant et al, PRL 125, 156601 (2020)

Up to 22, 24 sites

\(\mathcal{N} > 2\cdot 10^6\)

# non-zero el. \(> 3 \cdot 10^7 \)

23

Magnetization distributions

24

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Anderson chain / XX chain

N. Laflorencie, G. Lemarié, N. Macé, PRR 2, 042033(R) (2020)

J. C., N. Laflorencie, arXiv:2305.10574

Magnetization distributions

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Anderson chain / XX chain

\delta_i = 1/2 - | \langle S_i^z \rangle |

N. Laflorencie, G. Lemarié, N. Macé, PRR 2, 042033(R) (2020)

J. C., N. Laflorencie, arXiv:2305.10574

24

Magnetization distributions

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Anderson chain / XX chain

Heisenberg chain

\delta_i = 1/2 - | \langle S_i^z \rangle |

24

V. Khemani, F. Pollmann, and S. L. Sondhi, PRL 116, 247204 (2016)

S. P. Lim and D. N. Sheng, PRB 94, 045111 (2016)

D. J. Luitz and Y. Bar Lev, PRL 117, 170404 (2016)

M. Dupont and N. Laflorencie, PRB 99, 020202(R) (2019)

M. Hopjan and F. Heidrich-Meisner, Phys. Rev. A 101, 063617 (2020)

N. Laflorencie, G. Lemarié, N. Macé, PRR 2, 042033(R) (2020)

J. C., N. Laflorencie, arXiv:2305.10574

Magnetization distributions

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\(L\) increases

Anderson chain / XX chain

Heisenberg chain

\delta_i = 1/2 - | \langle S_i^z \rangle |

24

V. Khemani, F. Pollmann, and S. L. Sondhi, PRL 116, 247204 (2016)

S. P. Lim and D. N. Sheng, PRB 94, 045111 (2016)

D. J. Luitz and Y. Bar Lev, PRL 117, 170404 (2016)

M. Dupont and N. Laflorencie, PRB 99, 020202(R) (2019)

M. Hopjan and F. Heidrich-Meisner, Phys. Rev. A 101, 063617 (2020)

N. Laflorencie, G. Lemarié, N. Macé, PRR 2, 042033(R) (2020)

J. C., N. Laflorencie, arXiv:2305.10574

Magnetization distributions

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\(L\) increases

Anderson chain / XX chain

Heisenberg chain

\delta_i = 1/2 - | \langle S_i^z \rangle |

24

V. Khemani, F. Pollmann, and S. L. Sondhi, PRL 116, 247204 (2016)

S. P. Lim and D. N. Sheng, PRB 94, 045111 (2016)

D. J. Luitz and Y. Bar Lev, PRL 117, 170404 (2016)

M. Dupont and N. Laflorencie, PRB 99, 020202(R) (2019)

M. Hopjan and F. Heidrich-Meisner, Phys. Rev. A 101, 063617 (2020)

N. Laflorencie, G. Lemarié, N. Macé, PRR 2, 042033(R) (2020)

J. C., N. Laflorencie, arXiv:2305.10574

Magnetization distributions

25

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\(L\) increases

Anderson chain / XX chain

Heisenberg chain

\delta_i = 1/2 - | \langle S_i^z \rangle |

V. Khemani, F. Pollmann, and S. L. Sondhi, PRL 116, 247204 (2016)

S. P. Lim and D. N. Sheng, PRB 94, 045111 (2016)

D. J. Luitz and Y. Bar Lev, PRL 117, 170404 (2016)

M. Dupont and N. Laflorencie, PRB 99, 020202(R) (2019)

M. Hopjan and F. Heidrich-Meisner, Phys. Rev. A 101, 063617 (2020)

N. Laflorencie, G. Lemarié, N. Macé, PRR 2, 042033(R) (2020)

J. C., N. Laflorencie, arXiv:2305.10574

Minimal deviations in the XX chain  - TOy model

ED on one sample - XX (ANDERSON) CHAIN

J. C., N. Laflorencie, arXiv:2305.10574

26

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

ED on one sample - XX (ANDERSON) CHAIN

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

ED on one sample - XX (ANDERSON) CHAIN

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

ED on one sample - XX (ANDERSON) CHAIN

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

ED on one sample - XX (ANDERSON) CHAIN

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

Spin Freezing

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

Spin Freezing

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

\delta_i = 1/2 -| \langle S_i^z \rangle|

Some eigenstate

Spin Freezing

J. C., N. Laflorencie, arXiv:2305.10574

SPIN FREEZING!

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

\delta_i = 1/2 -| \langle S_i^z \rangle|

SPIN FREEZING!

Some eigenstate

Spin Freezing

J. C., N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

26

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Toy model : analytical description

27

|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Toy model : analytical description

27

|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

Toy model : analytical description

\Rightarrow \langle n_i \rangle = \langle S_i^z \rangle + 1/2 = \sum_{m \in {\color{#56B4E9}\mathrm{occ}}} |\phi_m(i)|^2

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

27

Minimal deviation?

28

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\delta_i = 1/2 -|\langle n_i \rangle -1/2|
|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

r
\delta_i = 1/2 -|\langle n_i \rangle -1/2|
\delta_i = \langle n_i \rangle
\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

28

r
\delta_i = 1/2 -|\langle n_i \rangle -1/2|
\delta_i = \langle n_i \rangle\approx e^{-\frac{r}{\xi} } + \dots
\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

28

r
\delta_i = 1/2 -|\langle n_i \rangle -1/2|
\delta_i = \langle n_i \rangle\approx e^{-\frac{r}{\xi} } + \dots
\ell_{\mathrm{cluster}}
\Rightarrow \quad \delta_{\min} \approx e^{-\frac{\ell_{\mathrm{cluster}}}{2\xi}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

28

r
\delta_i = 1/2 -|\langle n_i \rangle -1/2|
\delta_i = \langle n_i \rangle\approx e^{-\frac{r}{\xi} } + \dots
\ell_{\mathrm{cluster}}
\Rightarrow \quad \delta_{\min} \approx e^{-\frac{\ell_{\mathrm{cluster}}}{2\xi}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

|\phi_m(i)|^2 \propto \exp\left(-\frac{|i - i_0^m|}{{\xi}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

28

\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\delta_i = 1/2 -|\langle n_i \rangle -1/2|
\delta_i = \langle n_i \rangle\approx e^{-\frac{r}{\xi} } + \dots

\Rightarrow \quad \delta_{\min} \approx e^{-\frac{\ell_{\mathrm{cluster}}}{2\xi}}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

28

\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\delta_i = 1/2 -|\langle n_i \rangle -1/2|
\delta_i = \langle n_i \rangle\approx e^{-\frac{r}{\xi} } + \dots

\Rightarrow \quad \delta^{\mathrm{typ}}_{\min}= e^{\overline{\ln\delta_{\min}}} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

28

r
\ell_{\mathrm{cluster}}

29

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

r
\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}}
\overline{\ell_{\mathrm{cluster}}} \approx \frac{\ln L}{ \ln 2}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

29

r
\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}}
\overline{\ell_{\mathrm{cluster}}} \approx \frac{\ln L}{ \ln 2}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

29

r
\ell_{\mathrm{cluster}}

Minimal deviation?

Dupont, Macé, Laflorencie, PRB 100, 134201, (2019)

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}}
\overline{\ell_{\mathrm{cluster}}} \approx \frac{\ln L}{ \ln 2}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

29

\gamma

Exponent : toy model

 

JC, N. Laflorencie, arXiv:2305.10574

30

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}

Exponent : toy model

 

JC, N. Laflorencie, arXiv:2305.10574

\xi = \frac{1}{\ln\left(1+\left(\frac{W}{W_0}\right)^2 \right)}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

30

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}

Exponent : toy model

 

JC, N. Laflorencie, arXiv:2305.10574

\xi = \frac{1}{\ln\left(1+\left(\frac{W}{W_0}\right)^2 \right)}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

30

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}

Chain breaking

 

JC, N. Laflorencie, arXiv:2305.10574

31

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Chain breaking

 

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

31

\delta^{\mathrm{typ}}_{\min} = e^{\overline{\ln\delta_{\min}}} \approx L^{-\gamma_{\mathrm{typ}}(W)}

Chain breaking

 

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

31

\delta^{\mathrm{typ}}_{\min} = e^{\overline{\ln\delta_{\min}}} \approx L^{-\gamma_{\mathrm{typ}}(W)}

Chain breaking

 

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

31

\delta^{\mathrm{typ}}_{\min} = e^{\overline{\ln\delta_{\min}}} \approx L^{-\gamma_{\mathrm{typ}}(W)}

Exponents: XX CHain

32

 

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}

 

JC, N. Laflorencie, arXiv:2305.10574

ED

1/\gamma_{\mathrm{typ}}

Exponents: XX CHain

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

32

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}

 

JC, N. Laflorencie, arXiv:2305.10574

Excellent agreement ED  - Toy model !

ED

1/\gamma_{\mathrm{typ}}

Exponents: XX CHain

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

32

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}

 

JC, N. Laflorencie, arXiv:2305.10574

Excellent agreement ED  - Toy model !

ED

1/\gamma_{\mathrm{typ}}

Exponents: XX CHain

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

32

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}

Scaling

33

 

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}} ?

Scaling

 

JC, N. Laflorencie, arXiv:2305.10574

\(L \gg \xi\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

33

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}} ?

Scaling

 

JC, N. Laflorencie, arXiv:2305.10574

33

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\(L \gg \xi\)

\quad \delta^{\mathrm{typ}}_{\min} \approx e^{-\frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi}} ?
- \frac{\overline{\ell_{\mathrm{cluster}}}}{2\xi} -c

Quantitative description : Extreme value statistics

Tails and extremes

34

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Tails

Tails and extremes

34

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}

So far :

Extreme value

Tails

Tails and extremes

34

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}

So far :

Extreme value

Tails

Extreme value theory

Tails and extremes

35

\{X_i\}_{i = 1, 2, \dots, L} \sim p(x)
Y = \max(X_i)

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Z = \mathrm{rescaled}(Y)

Extreme value theory

Extreme value

Tails

Tails and extremes

35

\{X_i\}_{i = 1, 2, \dots, L} \sim p(x)
Y = \max(X_i)

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Power-law tail

Z = \mathrm{rescaled}(Y)

Extreme value theory

Extreme value

Tails

Tails and extremes

35

\{X_i\}_{i = 1, 2, \dots, L} \sim p(x)
Y = \max(X_i)

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Power-law tail

Z = \mathrm{rescaled}(Y)
z \sim \frac{\beta}{z^{1+\beta}} e^{-z^{-\beta}}

Fréchet law

Extreme value theory

Extreme value

Tails

Tails and extremes

35

\{X_i\}_{i = 1, 2, \dots, L} \sim p(x)
Y = \max(X_i)

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Power-law tail

Exponential tail

Gaussian tail

Z = \mathrm{rescaled}(Y)
z \sim \frac{\beta}{z^{1+\beta}} e^{-z^{-\beta}}

Fréchet law

Extreme value theory

Extreme value

Tails

Tails and extremes

35

\{X_i\}_{i = 1, 2, \dots, L} \sim p(x)
Y = \max(X_i)

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Power-law tail

Exponential tail

Gaussian tail

z \sim e^{-z - e^{-z}}

Gumbel law

Z = \mathrm{rescaled}(Y)
z \sim \frac{\beta}{z^{1+\beta}} e^{-z^{-\beta}}

Fréchet law

Extreme value theory

Extreme value

Tails

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

\mathcal{P}(\delta) \overset{\delta \rightarrow 0}{\sim} A\delta^{\alpha}

Extreme value theory - XX Chain

 

 

JC, N. Laflorencie, arXiv:2305.10574

36

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

Fréchet

\mathcal{P}(\delta) \overset{\delta \rightarrow 0}{\sim} A\delta^{\alpha}

Extreme value theory - XX Chain

 

 

JC, N. Laflorencie, arXiv:2305.10574

\mathcal{P}(\ln\delta_{\min}) \rightarrow AL\delta_{\min}^{\alpha} \exp\left({-\frac{AL}{\alpha+1}\delta_{\min}^{\alpha+1}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

36

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

Fréchet

\(10^5 \) samples

\mathcal{P}(\delta) \overset{\delta \rightarrow 0}{\sim} A\delta^{\alpha}

Extreme value theory - XX Chain

 

 

JC, N. Laflorencie, arXiv:2305.10574

\mathcal{P}(\ln\delta_{\min}) \rightarrow AL\delta_{\min}^{\alpha} \exp\left({-\frac{AL}{\alpha+1}\delta_{\min}^{\alpha+1}}\right)
\Delta_u= (\alpha+1)(\ln\delta_{\min}- \ln\delta_{\min}^{\mathrm{typ}})

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

37

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

Fréchet

\(10^5 \) samples

\mathcal{P}(\delta) \overset{\delta \rightarrow 0}{\sim} A\delta^{\alpha}

Extreme value theory - XX Chain

 

 

JC, N. Laflorencie, arXiv:2305.10574

\mathcal{P}(\ln\delta_{\min}) \rightarrow AL\delta_{\min}^{\alpha} \exp\left({-\frac{AL}{\alpha+1}\delta_{\min}^{\alpha+1}}\right)
\Delta_u= (\alpha+1)(\ln\delta_{\min}- \ln\delta_{\min}^{\mathrm{typ}})

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

37

\delta_{\mathrm{\min}}^{\mathrm{typ}}(L) \approx \left(\frac{A}{1+\alpha} L \right)^{-\frac{1}{1+\alpha}}

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

Fréchet

\(10^5 \) samples

\mathcal{P}(\delta) \overset{\delta \rightarrow 0}{\sim} A\delta^{\alpha}

Extreme value theory - XX Chain

 

 

JC, N. Laflorencie, arXiv:2305.10574

\mathcal{P}(\ln\delta_{\min}) \rightarrow AL\delta_{\min}^{\alpha} \exp\left({-\frac{AL}{\alpha+1}\delta_{\min}^{\alpha+1}}\right)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

37

\Delta_u= (\alpha+1)(\ln\delta_{\min}- \ln\delta_{\min}^{\mathrm{typ}})
\delta_{\mathrm{\min}}^{\mathrm{typ}}(L) \approx \left(\frac{A}{1+\alpha} L \right)^{-\frac{1}{1+\alpha}}

E. J. Gumbel, Statistics of Extremes, Dover, (1958, 2004)

S. N. Majumdar, A. Pal, G. Schehr, Physics Reports, 840, 1 (2020)

Fréchet

\(10^5 \) samples

\mathcal{P}(\delta) \overset{\delta \rightarrow 0}{\sim} A\delta^{\alpha}

Extreme value theory - XX Chain

 

 

JC, N. Laflorencie, arXiv:2305.10574

\mathcal{P}(\ln\delta_{\min}) \rightarrow AL\delta_{\min}^{\alpha} \exp\left({-\frac{AL}{\alpha+1}\delta_{\min}^{\alpha+1}}\right)
\Delta_u= (\alpha+1)(\ln\delta_{\min}- \ln\delta_{\min}^{\mathrm{typ}})

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

37

\delta_{\mathrm{\min}}^{\mathrm{typ}}(L) \approx \left(\frac{A}{1+\alpha} L \right)^{-\frac{1}{1+\alpha}}

EXPONENT : POWER-LAW

 

JC, N. Laflorencie, arXiv:2305.10574

38

ED

1/\gamma_{\mathrm{typ}}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}

 

JC, N. Laflorencie, arXiv:2305.10574

1+\alpha

ED

1/\gamma_{\mathrm{typ}}

EXPONENT : POWER-LAW

38

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\delta^{\mathrm{typ}}_{\min} \approx L^{-\frac{1}{2\xi \ln2}}
\delta^{\mathrm{typ}}_{\min} \approx L^{-\gamma_{\mathrm{typ}}(W)}
\delta_{\mathrm{\min}}^{\mathrm{typ}}(L) \approx \left(\frac{A}{1+\alpha} L \right)^{-\frac{1}{1+\alpha}}

Consequences : interacting system

39

Effect of interactions?

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\mathcal{H} = \mathcal{H}_{XX} + \Delta \sum_i S_i^z S_{i+1}^z

"Stability" of the cluster with respect to the  interactions?

 

 

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

40

Effect of interactions?

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

disorder

increases

 

 

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

40

Effect of interactions?

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

disorder

increases

\(\delta_i\) \(\rightarrow\) 1/2 (\(\langle S^z_i\rangle \rightarrow 0\))

Empty circles: 

Heisenberg

 

 

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

40

Effect of interactions?

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

disorder

increases

Empty circles: 

Heisenberg

 

 

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\(\delta_i\) \(\rightarrow\) 1/2 (\(\langle S^z_i\rangle \rightarrow 0\))

41

Exponent

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

At strong disorder, \(\gamma \sim 1/\xi\)

\gamma

\(\Rightarrow \) Interpretation of the exponent as related to a many-body localization length

 

 

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

42

Exponent

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

At strong disorder, \(\gamma \sim 1/\xi\)

\gamma

\(\Rightarrow \) Interpretation of the exponent as related to a many-body localization length

 

 

Laflorencie, Lemarié, Macé, PRR 2, 042033(R), (2020)

JC, N. Laflorencie, arXiv:2305.10574

\(\Lambda\) : disorder-dependent non-ergodicity volume

\(\lambda\) : interpreted as a localization length

43

Extreme value distributions

Conjecture : Gumbel (?) on the Ergodic side, Fréchet on the MBL side.

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

 

 

 

JC, N. Laflorencie, arXiv:2305.10574

\(W = 2\)

43

Extreme value distributions

Conjecture : Gumbel (?) on the Ergodic side, Fréchet on the MBL side.

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

 

 

 

JC, N. Laflorencie, arXiv:2305.10574

\(W = 2\)

43

Conjecture : Gumbel (?) on the Ergodic side, Fréchet on the MBL side.

\(\Delta = 0\)

\(\Delta = 1\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Extreme value distributions

 

 

 

JC, N. Laflorencie, arXiv:2305.10574

43

Conjecture : Gumbel (?) on the Ergodic side, Fréchet on the MBL side.

\(\Delta = 0\)

\(\Delta = 1\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Extreme value distributions

 

 

 

JC, N. Laflorencie, arXiv:2305.10574

{\rm{KL}}(p|q)= \sum_i q_i \ln \frac{q_i}{p_i}

Kullback-Leibler divergence :

44

Kullback-Leibler divergence

 

S. Kullback and R. A. Leibler, The annals of mathematical statistics 22, 79 (1951)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

{\rm{KL}}(p|q)= \sum_i q_i \ln \frac{q_i}{p_i}

Kullback-Leibler divergence :

44

Kullback-Leibler divergence

 

S. Kullback and R. A. Leibler, The annals of mathematical statistics 22, 79 (1951)

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

 

E. H. V. Doggen et al., PRB 98, 174202 (2018)

See e.g. D. Sels, PRB  106 , L020202 (2022)

{\rm{KL}}(p|q)= \sum_i q_i \ln \frac{q_i}{p_i}

Kullback-Leibler divergence :

44

Consequences : Heisenberg

 

E. H. V. Doggen et al., PRB 98, 174202 (2018)

See e.g. D. Sels, PRB  106 , L020202 (2022)

 

S. Kullback and R. A. Leibler, The annals of mathematical statistics 22, 79 (1951)

JC, N. Laflorencie, arXiv:2305.10574

  • Transition in the extreme value distributions

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

{\rm{KL}}(p|q)= \sum_i q_i \ln \frac{q_i}{p_i}

Kullback-Leibler divergence :

44

Consequences : Heisenberg

  • Transition in the extreme value distributions
  • Coinciding with the MBL transition?

 

E. H. V. Doggen et al., PRB 98, 174202 (2018)

See e.g. D. Sels, PRB  106 , L020202 (2022)

 

S. Kullback and R. A. Leibler, The annals of mathematical statistics 22, 79 (1951)

JC, N. Laflorencie, arXiv:2305.10574

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

{\rm{KL}}(p|q)= \sum_i q_i \ln \frac{q_i}{p_i}

Kullback-Leibler divergence :

Take home message

SPIN FREEZING!

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

45

Take home message

SPIN FREEZING!

XX chain :

  • controlled by largest cluster of occupied orbitals

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

45

Take home message

SPIN FREEZING!

XX chain :

  • controlled by largest cluster of occupied orbitals
  • Excellent fits & collapses with a Fréchet Law

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

45

Take home message

SPIN FREEZING!

XX chain :

  • controlled by largest cluster of occupied orbitals

 Heisenberg chain at strong disorder:

Chain breaks!

W

No chain breaks

Chain breaks

  • Excellent fits & collapses with a Fréchet Law

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

45

Take home message

SPIN FREEZING!

XX chain :

  • controlled by largest cluster of occupied orbitals

 Heisenberg chain at strong disorder:

Chain breaks!

W

No chain breaks

Chain breaks

  • Excellent fits & collapses with a Fréchet Law

Comparing \(\delta_{\min}\) deviation in Heisenberg vs Many-body Anderson:

Extreme value transition characterized by the

KL divergence.

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

45

Take home message

SPIN FREEZING!

XX chain :

  • controlled by largest cluster of occupied orbitals

 Heisenberg chain at strong disorder:

Chain breaks!

W

No chain breaks

Chain breaks

  • Excellent fits & collapses with a Fréchet Law

Comparing \(\delta_{\min}\) deviation in Heisenberg vs Many-body Anderson:

Extreme value transition characterized by the

KL divergence.

Thank you for your attention!

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

45

good question!

Anderson Localization : example

1 particle

11

Billy J, et al.  Direct observation of Anderson localization of matter waves in a controlled disorder. Nature. 2008

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

AL vs MBL

No spreading of entanglement

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Weak interactions and disorder

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Analytical, general picture:

Interactions \(\Rightarrow\) transition between weak and strong disorder

L. Fleischman, P. W. Anderson, PRB 2, 2336 (1980) \(\rightarrow\) single-particle excitations and conditions for Anderson transition

B. Altschuler, Y. Gefen, A. Kamenev, L. S. Levitov, PRL 78,  2803, (1997) \(\rightarrow\) quasi particle lifetime & localization in Fock space

P. Jacquod, D. L. Shepelyansky, PRL 79, 1837 (1997) \(\rightarrow\) Gap ratio statistics, finite systems

I. V. Gornyi, A. D. Mirlin, D. G. Polyakov, PRL 95, 206603 (2005) \(\rightarrow\) zero  conductivity at low temperature

*D. M. Basko, I. L. Aleiner, B. L. Altschuler, Annals of Physics 321, 1126 (2006) \(\rightarrow\) metal-insulator transition, localization in Fock space

I.L. Aleiner, B. L. Altshuler, G. V Shlyapnikov, Nature Physics 6, 900-904 (2010) \(\rightarrow\) weakly interacting bosons

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]

disorder

interactions

Anderson localized

Delocalized

Ergodic

Insulator

ED : Why

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

High energy eigenstates, high dos

Potential absence of thermalization

Simulations of Many-Body Localizable (MBL) lattices models | Fabien Alet | Cargese

Cannot use stochastic methods

Usual condensed matter methods target the ground state.

\(\rightarrow\) DMRG-X, RSRG-X,  time evolution with MPS, Unitary flow, ...

Ideally should work on both sides of the transition

Eigenstate thermalization hypothesis

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Fate of isolated many-body quantum systems?

\(\leftrightarrow\) A question from quantum chaos:

Thermal average 

Time average

?

ETH

J. M. Deutsch , PRA. 43, 2046–2049, (1991) , M. Srednicki, PRE 50,  888–901, (1994)

L. D’Alessio, Y. Kafri, A. Polkovnikov, and M. Rigol, Adv. Phys. 65, 239 (2016)

Eigenstate thermalization hypothesis

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Fate of isolated many-body quantum systems?

\(\leftrightarrow\) A question from quantum chaos:

Thermal average 

Time average

?

ETH

J. M. Deutsch , PRA. 43, 2046–2049, (1991) , M. Srednicki, PRE 50,  888–901, (1994)

L. D’Alessio, Y. Kafri, A. Polkovnikov, and M. Rigol, Adv. Phys. 65, 239 (2016)

(i) diagonal elements of local observables are smooth functions of the energy and take their microcanonical average value

(ii)off-diagonal elements vanish in the thermodynamic limit like \(e^{(-E_m -E_n)/2}\)

Statement about high energy.

Heisenberg: Many-Body Localization

Morningstar et al, PRB 105, 174205 (2022)

Fate of isolated quantum many-body systems ? 

\mathcal{H}_f = \sum_{i} \Bigl[\frac{J}{2}\left({\color{lightgreen}c_i^{\dagger} c_{i+1}^{\vphantom{\dagger}} + c_{i+1}^{\dagger}c_i^{\vphantom{\dagger}}}+{\color{#b4a7d6}2 \Delta n_i n_{i+1}} \right) -{\color{#76a5af}h_i n_i}\Bigr]
\mathcal{H} = \sum_{i} \frac{J}{2}\left({\color{lightgreen}S_i^{+} S_{i+1}^{-} + S_i^{-} S_{i+1}^{+}} + {\color{#b4a7d6} 2\Delta S_i^z S_{i+1}^z}\right) - \sum_{i} {\color{#76a5af} h_i S_i^z}

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Kane-fisher

LL + weakened link can flow to

an opened chain. 

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Entanglement entropy

N. Laflorencie, in A. Bayat et al. (eds.), Entanglement in Spin Chains,

Quantum Science and Technology, https://doi.org/10.1007/978-3-031-03998-0_4

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distributions of minimal deviations

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Distributions of minimal deviations

 

JC, Laflorencie, In preparation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Cluster lengths

 

JC, Laflorencie, In preparation

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Power-law tails?

 

JC, N. Laflorencie, arXiv:2305.10574

\delta_{\min} \sim e^{-\frac{\ell}{2\xi}}

\( \Rightarrow \delta\) occurs if there is \(\ell \geq -2 \xi \ln(\delta)\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\ell
\mathcal{P}(\ell) \propto 2^{-\ell}

Very roughly:

 

\Rightarrow \mathcal{P}_L(\ln(\delta)) \propto \exp\left(2\xi\ln2 \times \ln(\delta)\right)

Power-law tails?

 

JC, N. Laflorencie, arXiv:2305.10574

\delta_{\min} \sim e^{-\frac{\ell}{2\xi}}

\( \Rightarrow \delta\) occurs if there is \(\ell \geq -2 \xi \ln(\delta)\)

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\ell
\mathcal{P}(\ell) \propto 2^{-\ell}

Very roughly:

 

\mathcal{P}_L(\delta) \propto \delta^{\left(2\xi\ln2-1\right)}
\Rightarrow \mathcal{P}_L(\ln(\delta)) \propto \exp\left(2\xi\ln2 \times \ln(\delta)\right)

Experiments

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

PROBES

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

"Dynamical" probes

"Static" probes

Entanglement

entropy (EE)

Multifractality (participation entropy)

Entanglement spectrum (ES)

and these probes -->

Spectral repulsion

Magnetization & extremal magnetization

-> Lcluster, delta min

Evolution / autocorrelation of a prepared state

Out-of-Time-Order Correlator (OTOC)

KL divergence between eigenstates

Increasing number of involved states

Gap ratio

two-eigenstates correlation functions

Spectral form factor

Level compressibility

Imbalance

Dream: LIOMs

(minimal correlator)

Many-body resonances between eigenstates

Minimal gap

Distribution of matrix elements?

Heisenberg: Ergodic to MBL 

Fate of isolated quantum many-body systems ? 

\(\frac{E -E_{\min}}{E_{\max}-E_{\min}}\)

D. J. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015) 

\(S_E\) : Entanglement entropy (red: visual estimate)

\(r\) : Gap ratio

\(\mathcal{F}\) : Bipartite fluctuations

\(\mathcal{F} = \langle (S_A^z)^2 \rangle - \langle  S_A^z \rangle ^2 \)

\(S_1^{P} = a_1 \ln(\mathrm{dim} H) = - \sum_i p_i \ln(p_i)\) : partitipation entropy (multifractality)

\( f \) : dynamic fraction of an
initial spin polarization

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Hilbert-space localization

|\Psi\rangle = \sum_{\alpha = 1}^{\mathcal{N}} \psi_{\alpha} |\alpha \rangle
S_q = \frac{1}{1-q} \ln\left(\sum_{\alpha=1}^{\mathcal{N}} |\psi_{\alpha}|^{2q}\right)
\mathcal{N} = \text{ Hilbert space dim.}

Participation entropies

Basis-dependent

Macé, Alet, Laflorencie, PRL 123, 180601 (2019)

POLFED

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Ground state phase diagram 

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

\Delta
h
\Delta = 0
\Delta = -1

Bose glass:  

gapless, but exponentially decaying correlations

finite compressibility

insulating; localized

infinite superfluid susceptibility

\Delta = -1/2

BKT from SDRG:

K > 3/2

Weak link physics

 

 

Superfluid

Dynamic fraction

D. J. Luitz, N. Laflorencie, F. Alet, PRB 91, 081103(R) (2015) 

J. COLBOIS | QIMG 2023 , KYOTO | 27.09.2023

Extreme Statistics in Random spin chains

By Jeanne Colbois

Extreme Statistics in Random spin chains

Talk at "Quantum information, quantum matter and quantum gravity", Kyoto 2023

  • 76