scholarly journals Merging Dirac points and topological phase transitions in the tight-binding model on the generalized honeycomb lattice

2012 ◽  
Vol 86 (16) ◽  
Author(s):  
Yasumasa Hasegawa ◽  
Keita Kishigi
Keyword(s):  
Phase Transitions ◽  
Tight Binding ◽  
Honeycomb Lattice ◽  
Topological Phase ◽  
Tight Binding Model ◽  
Binding Model ◽  
Topological Phase Transitions

scholarly journals Topological phase transitions in the non-Abelian honeycomb lattice

2010 ◽  
Vol 12 (3) ◽  
pp. 033041 ◽  
Author(s):  
A Bermudez ◽  
N Goldman ◽  
A Kubasiak ◽  
M Lewenstein ◽  
M A Martin-Delgado
Keyword(s):  
Phase Transitions ◽  
Honeycomb Lattice ◽  
Topological Phase ◽  
Topological Phase Transitions

Topological phase transition of two-dimensional topological polaritons

2017 ◽  
Vol 31 (11) ◽  
pp. 1750070
Author(s):  
Zimeng Chi ◽  
Xiaoyong Guo ◽  
Zaijun Wang
Keyword(s):  
Phase Transitions ◽  
Energy Gap ◽  
Tight Binding ◽  
Quantum Spin ◽  
Generic Model ◽  
Topological Phase ◽  
Two Dimensional ◽  
Strongly Coupled ◽  
Bulk Energy ◽  
Topological Phase Transitions

Topological phase transitions of a two-dimensional topologically nontrivial polaritonic system are studied. A generic model of semiconductor excitons strongly coupled with tailored photonic modes is considered. We introduce a pseudospin operator, measuring the polariton polarization between photonic-like and excitonic-like. The associated pseudospin spectrum and pseudospin Chern numbers are calculated. It is shown that the pseudospin Chern number phase diagram exhibits certain features resembling the topological phase of quantum-spin-Hall-like. Moreover, a series of topological phase transitions may occur with the closing of the bulk energy gap or the pseudospin spectrum gap. In a tight-binding form, the edge-mode simulation is done numerically to confirm the analytically results.

scholarly journals Tight-binding model investigation of the biaxial strain induced topological phase transition in GeCH3

2017 ◽  
Vol 96 (8) ◽  
Author(s):  
Mohsen Rezaei ◽  
Esmaeil Taghizadeh Sisakht ◽  
Farhad Fazileh ◽  
Zahra Aslani ◽  
F. M. Peeters
Keyword(s):  
Phase Transition ◽  
Tight Binding ◽  
Model Investigation ◽  
Topological Phase ◽  
Tight Binding Model ◽  
Biaxial Strain ◽  
Binding Model ◽  
Topological Phase Transition

Topological phase transitions of three-dimensional topological insulator without energy gap closing

2015 ◽  
Vol 29 (28) ◽  
pp. 1550199 ◽  
Author(s):  
Zimeng Chi ◽  
Xiaoyong Guo ◽  
Zaijun Wang ◽  
Qiang Zheng
Keyword(s):  
Phase Transitions ◽  
Topological Insulator ◽  
Energy Gap ◽  
Strong Field ◽  
Tight Binding ◽  
Three Dimensional ◽  
Flat Band ◽  
Topological Phase ◽  
Exchange Field ◽  
Topological Phase Transitions

In this paper, we demonstrate an anomalous topological phase transition without closing of bulk energy gap. We find such an effect in a model of three-dimensional (3D) topological insulator (TI) subjected to the in-plane exchange field. The energy spectrum, spin spectrum and momentum-dependent spin Chern numbers are calculated. It is shown that our system realizes both the 3D TI phase and the integer quantum Hall (QH) phase. By varying the strength of exchange field, a series of topological phase transitions takes place and in the mean time the energy gap remains open. However, the spin spectrum is closed at the transition and various topological phases are characterized with different number of nodes in spin spectrum. In a tight-binding form, the surface modes are discussed to confirm with the phase diagram. Particularly for a strong field, we find the flat band edge modes which may provide an opportunity for realizing the two-dimensional (2D) fractional QH effect on the boundary of our 3D system.

scholarly journals Creating polar antivortex in PbTiO3/SrTiO3 superlattice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adeel Y. Abid ◽  
Yuanwei Sun ◽  
Xu Hou ◽  
Congbing Tan ◽  
Xiangli Zhong ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Phase Field ◽  
Driving Force ◽  
Topological Phase ◽  
Phase Field Simulation ◽  
Topological Structures ◽  
Field Simulation ◽  
Condensed Matters ◽  
Topological Phase Transitions ◽  
Insight Into

AbstractNontrivial topological structures offer a rich playground in condensed matters and promise alternative device configurations for post-Moore electronics. While recently a number of polar topologies have been discovered in confined ferroelectric PbTiO3 within artificially engineered PbTiO3/SrTiO3 superlattices, little attention was paid to possible topological polar structures in SrTiO3. Here we successfully create previously unrealized polar antivortices within the SrTiO3 of PbTiO3/SrTiO3 superlattices, accomplished by carefully engineering their thicknesses guided by phase-field simulation. Field- and thermal-induced Kosterlitz–Thouless-like topological phase transitions have also been demonstrated, and it was discovered that the driving force for antivortex formation is electrostatic instead of elastic. This work completes an important missing link in polar topologies, expands the reaches of topological structures, and offers insight into searching and manipulating polar textures.

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