Revealing the topological phase diagrams of 2D heterostructures using SIESTA
ELTE
Zoltán Tajkov
Kick-off meeting 2024.09.26
outline
siesta
Powerful DFT tool utilizing localized basis set. This means it provides a tight-binding Hamiltonian. Also models open-boundary systems.
bitei / graphene
Mechanical strain induces topological phase transition in graphene / bitei heterostructures
zrte5
Using the SIESTA code we were able to clear out the confusion around the peculiar properties of ZrTe5
SIESTA
Capabilities
- Total and partial energies.
- Atomic forces.
- Geometry relaxation, fixed or variable cell.
- Spin polarized calculations (collinear or not).
- Local and orbital-projected density of states.
- Band structure.
- Model open-boundary systems (TRANS-SIESTA)
Standard DFT stuff
SIESTA
Capabilities
Model open-boundary systems (TRANS-SIESTA)
Standard DFT stuff
SIESTA
Capabilities
Model open-boundary systems (TRANS-SIESTA)
Standard DFT stuff
outline
siesta
Powerful DFT tool utilizing localized basis set. This means it provides a tight-binding Hamiltonian. Also models open-boundary systems.
bitei / graphene
Mechanical strain induce topological phase transition in graphene / bitei heterostructures
zrte5
Using the SIESTA code we were able to clear out the confusion around the peculiar properties of ZrTe5
bitei / graphene systems
BiTeI sandwich: Kou et al. ACS Nano, 8 10448 (2014)
Z. Tajkov et al. Nanoscale 11, 12704 (2019)
bitei / graphene systems
BiTeI sandwich: Kou et al. ACS Nano, 8 10448 (2014)
Z. Tajkov et al. Nanoscale 11, 12704 (2019)
bitei / graphene systems
Z. Tajkov et al. Nanoscale 11, 12704 (2019)
Tini-Tiny
trivial gap
bitei / graphene systems
Z. Tajkov et al. Nanoscale 11, 12704 (2019)
Not so tiny
topological gap
in-plane strain
Tini-Tiny
trivial gap
bitei / graphene systems
Z. Tajkov et al. Appl. Sci. 2019, 9(20), 4330
bitei / graphene systems
Z. Tajkov et al. Appl. Sci. 2019, 9(20), 4330
Tight-binding level
outline
siesta
Powerful DFT tool utilizing localized basis set. This means it provides a tight-binding Hamiltonian. Also models open-boundary systems.
bitei / graphene
Mechanical strain induce topological phase transition in graphene / bitei heterostructures
zrte5
Using the SIESTA code we were able to clear out the confusion around the peculiar properties of ZrTe5
zrte5
zrte5
zrte5
$$ \#1 $$
$$ \#2 $$
$$ d $$
$$ h$$
$$ R_1 $$
$$ R_2 $$
$$ Ang $$
55
49
1015
813
178
90
6000
4560
zrte5
$$ O_x $$
$$ \mathcal{A}_1 $$
$$ \mathcal{B}_1 $$
$$ C $$
$$ O_z$$
$$ O_x $$
$$ \mathcal{A}_1 $$
$$ \mathcal{B}_1 $$
$$ C $$
$$ O_z$$
Stiffness tensor (DFT)
Finite Element Method
Electric properties (DFT)
zrte5
COMSOL and DFT
zrte5
Ab initio
zrte5
Monolayer
zrte5
Bilayer
Phase diagrams
USING
SIESTA
Correlated states on the Hill
HUN-REN Centre for Energy Research
Capabilities in 2D
- Corralated states
- Topological states
- Small angle moiré
PEOPLE
Péter Nemes-Incze
Levente Tapasztó
Péter Vancsó
Talk at TRILMAX
By novidad21
