A Quantized Interband Topological Index in Two-Dimensional Systems
- URL: http://arxiv.org/abs/2307.16893v1
- Date: Mon, 31 Jul 2023 17:59:03 GMT
- Title: A Quantized Interband Topological Index in Two-Dimensional Systems
- Authors: Tharindu Fernando, Ting Cao
- Abstract summary: We introduce a novel gauge-invariant, quantized interband index in two-dimensional (2D) multiband systems.
We confirm its topological nature by numerically demonstrating a one-to-one correspondence to the valley Chern number.
We derive a band-resolved topological charge and demonstrate that it can be used to investigate the nature of edge states due to band inversion in valley systems like multilayer graphene.
- Score: 3.980928498919734
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We introduce a novel gauge-invariant, quantized interband index in
two-dimensional (2D) multiband systems. It provides a bulk topological
classification of a submanifold of parameter space (e.g., an electron valley in
a Brillouin zone), and therefore overcomes difficulties in characterizing
topology of submanifolds. We confirm its topological nature by numerically
demonstrating a one-to-one correspondence to the valley Chern number in $k\cdot
p$ models (e.g., gapped Dirac fermion model), and the first Chern number in
lattice models (e.g., Haldane model). Furthermore, we derive a band-resolved
topological charge and demonstrate that it can be used to investigate the
nature of edge states due to band inversion in valley systems like multilayer
graphene.
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