LPT Toulouse - FFC Journal Club | 09.01.2023 | J. Colbois
arXiv:2211.13089 (v1)
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Need
Idea
Promise
M
+ Combine efficiently
109 non-interacting
106 Two interacting particles
Time evolution
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(1) Mostly: ti,i+1=t=1, ϵi :
Irrational β
(2) Also:
ϵi constant
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arXiv:2211.13089 (v1)
(1) Mostly: ti,i+1=t=1, ϵi :
Irrational β
(2) Also:
ϵi constant
More delocalized
Chiral (particle-hole) symmetry:
Delocalized region
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arXiv:2211.13089 (v1)
Only at strong disorder
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Density of states
Localization length
Participation ratio
D J Thouless 1972 J. Phys. C: Solid State Phys. 5 77
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Parallelization
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Repetitions
L−M sub-systems
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Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
Repetitions
L−M sub-systems
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Repetitions
L−M sub-systems
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⌈M2L⌉ sub-systems
Far less repetitions
M twice as large
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
⌈M2L⌉ sub-systems
Far less repetitions
M twice as large
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
⌈M2L⌉ sub-systems
Far less repetitions
M twice as large
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
⌈M2L⌉ sub-systems
Far less repetitions
M twice as large
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
⌈M2L⌉ sub-systems
Far less repetitions
M twice as large
Repetitions
L−M sub-systems
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arXiv:2211.13089 (v1)
⌈M2L⌉ sub-systems
Far less repetitions
M twice as large
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Real
Spurious
Bi−1
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∣Φ⟩ localized in S :
Variance w.r.t environment
∣Φ⟩ eigenvector of HS:
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Alternative : Gram-Schmidt
Two steps:
No arbitrary cut-off
Much slower
1. ∣EΦ−EΦk∣>num.err∀k∈rel.clusters
2. ⟨Φj∣Φ⟩<θ for all relevant k
⇒ ∣Φ⟩ is a new eigenfunction
Setting θ :
Pop. on each site should not be larger than 1.
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arXiv:2211.13089 (v1)
Two steps:
1. ∣EΦ−EΦk∣>num.err∀k∈rel.clusters
2. ⟨Φj∣Φ⟩<θ for all relevant k
⇒ ∣Φ⟩ is a new eigenfunction
Setting θ :
Pop. on each site should not be larger than 1.
Parallelization:
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Prec. ϵ on ⟨O^⟩ ⇒
# Eigenfunctions:
Accuracy of eigenfunctions:
Valid eigenfunctions : variance smaller than δ2
(Err. δ in amplitude)
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S=[α,Ω]
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Here ∣Φi∣2=∑j∣⟨i,j∣Φ⟩∣2
Smaller than a given cut-off.
Increase M: new eigenstates, but independent of the value of the interaction
arXiv:2211.13089 (v1)
Parameters
σ
θ,δ(ϵ)
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MMax=26000
⇒VMin=0.05: WAnd.box∼0.77; WAnd.Gauss.=WAnd.Bin. ∼0.44
Variance:
Time evolution:
MMax=200
Variance:
Overlap:
θ=10−5
Overlap:
θ=10−7
Time evolution:
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M∝ξ
Assume
Limitations:
ξ∼L (ergodic) → usual complexity
ξ≪L → Dep. L : locally larger M
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4 cores Inter Core i7-7700 CPU
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M
Potential variance
arXiv:2211.13089 (v1)
S. Aubry and G. André, Ann. Israel Phys. Soc 3, 18, (1980)
Strong
Weak
Single Particle
Two Interacting Particles
Eigenfunctions / Dynamics
Disorder
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109 sites, Box distribution
WAnd.=10
WMBL=2.5
WAnd.=20
WMBL=5
WAnd.=40
WMBL=10
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Diff.
U=0
U=2
L=105,WAnd.=10
Box distribution
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U=10,L=106,WAnd.=40
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U=10,L=106,WAnd.=40
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D.O.S., V=0.05, i.e. WBox,MBL= ; L=108 sites
arXiv:2211.13089 (v1)
Cusp : M. Kappus and F. Wegner,
Zeit. Phys. B 45,15–21 (1981)
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Localization length, V=0.05, i.e. WBox,MBL= ; L=108 sites
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G. Czycholl, B. Kramer, and A. MacKinnon, Zeit. Phys. B 43, 5–11 (1981)
M. Kappus and F. Wegner, Zeit. Phys. B 45,15–21 (1981)
B. Kramer and A. MacKinnon, Rep. Prog. Phys. 56, 1469 (1993)
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Localization length, L=108 sites
arXiv:2211.13089 (v1)
G. Czycholl, B. Kramer, and A. MacKinnon, Zeit. Phys. B 43, 5–11 (1981)
M. Kappus and F. Wegner, Zeit. Phys. B 45,15–21 (1981)
B. Kramer and A. MacKinnon, Rep. Prog. Phys. 56, 1469 (1993)
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L=108, Box distribution, V=0.05
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L=108, Box distribution, V=0.05
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L=108, Box distribution, V=0.05
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L=106, WAnd=4
V=4
L=106, WAnd=6
V=3
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L=106, WAnd=4
V=4
L=106, WAnd=6
V=3
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L=106, WAnd=4
V=4
L=106, WAnd=6
V=3
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L=106, WAnd=6
V=3
L=106, WAnd=4
V=4
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L=106, WAnd=6
V=3
L=106, WAnd=4
V=4
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L=106, WAnd=6
V=3
L=106, WAnd=4
V=4
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L=106, WAnd=6
V=3
L=106, WAnd=4
V=4
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Aubry-André model
L=108 sites
S. Aubry and G. André, Ann. Israel Phys. Soc 3, 18, (1980)
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Bond disorder
L=108 sites
arXiv:2211.13089 (v1)
M=104,99.8% of eigenstates
Δt=0.5
Divergence : L. Balents and M. P. A. Fisher, Phys. Rev. B 56, 12970 (1997)
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Bond disorder
L=108 sites
arXiv:2211.13089 (v1)
M=104,99.8% of eigenstates
Δt=0.5
Divergence : L. Balents and M. P. A. Fisher, Phys. Rev. B 56, 12970 (1997)
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Bond disorder
L=108 sites
arXiv:2211.13089 (v1)
M=104,99.8% of eigenstates
Δt=0.5
Divergence : L. Balents and M. P. A. Fisher, Phys. Rev. B 56, 12970 (1997)
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Bond disorder
L=108 sites
arXiv:2211.13089 (v1)
M=104,99.8% of eigenstates
Δt=0.5
Divergence : L. Balents and M. P. A. Fisher, Phys. Rev. B 56, 12970 (1997)
Evolution of localized wavefunctions
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Long-time limit
Strong disorder, L=109
t∈[9.500,10.500]
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Long-time limit
Strong disorder, L=109
t∈[9.500,10.500]
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Long-time limit
Strong disorder, L=109
t∈[9.500,10.500]
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Long-time limit
Strong disorder, L=109
t∈[9.500,10.500]
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L=106
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L=106
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Long-time limit
L=106
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Weak disorder,
L=108
Box, V=0.05
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Weak disorder,
L=108
Box, V=0.05
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