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arXiv · 1901.06820

Finite-size effects in non-Hermitian topological systems

Rui Chen·Chui-Zhen Chen·Bin Zhou·Dong-Hui Xu
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Abstract

We systematically investigate the finite-size effects in non-Hermitian one-dimensional (1D) Su-Schrieffer-Heeger (SSH) and two-dimensional (2D) Chern insulator models. Using a combination of analytical and numerical calculations, we show that the non-Hermitian intra-cell hoppings in the SSH model can modify the localization lengths of bulk and end states, giving rise to a complex finite-size energy gap that exhibits an oscillating exponential decay as the chain length grows. However, the imaginary staggered on-site potentials in the SSH model only change the end-state energy, leaving the localization lengths of the system unchanged. In this case, the finite-size energy gap can undergo a transition from real values to imaginary values. We observed similar phenomena for the finite-size effect in 2D Chern insulator systems.

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Rui Chen, Chui-Zhen Chen, Bin Zhou, Dong-Hui Xu. 2019-04-17. Finite-size effects in non-Hermitian topological systems. https://doi.org/10.1103/physrevb.99.155431

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