Geometric Response and Disclination-Induced Skin Effects in Non-Hermitian Systems

• URL: http://arxiv.org/abs/2102.05667v2
• Date: Tue, 10 Aug 2021 05:51:36 GMT
• Title: Geometric Response and Disclination-Induced Skin Effects in Non-Hermitian Systems
• Authors: Xiao-Qi Sun, Penghao Zhu, Taylor L. Hughes
• Abstract summary: We study the geometric response of three-dimensional non-Hermitian crystalline systems with nontrivial point-gap topology. For systems with fourfold rotation symmetry, we show that in the presence of disclination lines with a total Frank angle which is an integer multiple of $2pi$, there can be nontrivial one-dimensional point-gap topology along the direction of the disclination lines.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We study the geometric response of three-dimensional non-Hermitian crystalline systems with nontrivial point-gap topology. For systems with fourfold rotation symmetry, we show that in the presence of disclination lines with a total Frank angle which is an integer multiple of $2\pi$, there can be nontrivial one-dimensional point-gap topology along the direction of the disclination lines. This results in disclination-induced non-Hermitian skin effects. By doubling a non-Hermitian Hamiltonian to a Hermitian three-dimensional chiral topological insulator, we show that the disclination-induced skin modes are zero modes of the effective surface Dirac fermion(s) in the presence of a pseudomagnetic flux induced by disclinations. Furthermore, we find that our results have a field theoretic description, and the corresponding geometric response actions (e.g., the Euclidean Wen-Zee action) enrich the topological field theory of non-Hermitian systems.

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