Measuring Non-Hermitian Topological Invariants Directly from Quench Dynamics

Fuente: arXiv
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Main Authors: Lin, Xiao-Dong, Zhang, Long
Format: Preprint
Published: 2024
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author Lin, Xiao-Dong
Zhang, Long
author_facet Lin, Xiao-Dong
Zhang, Long
contents While non-Hermitian (NH) topological phases and phenomena have been observed across various quantum systems, directly measuring NH topological invariants remains a significant challenge. In this study, we present a generic and unified framework for the direct measurement of various NH topological invariants in odd-dimensional systems through quench dynamics. We demonstrate that in one-dimensional (1D) NH systems with sublattice symmetry, the line-gap winding number and point-gap braiding degree can be extracted from the winding patterns of a dynamically constructed field based on post-quench spin textures. Specifically, line-gap topology is characterized by integer-valued winding, whereas point-gap complex-band braiding is revealed by half-integer or integer winding with abrupt jumps. We also extend our approach to higher-dimensional winding numbers and non-Bloch topological invariants under open-boundary conditions. Additionally, we propose a practical cold-atom setup to realize and detect 1D NH topological phases, showing that our dynamical measurement scheme is feasible in current experimental settings. This work paves the way for the direct measurement of NH topological invariants in quantum systems.
format Preprint
id arxiv_https___arxiv_org_abs_2410_13241
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Measuring Non-Hermitian Topological Invariants Directly from Quench Dynamics
Lin, Xiao-Dong
Zhang, Long
Quantum Gases
Mesoscale and Nanoscale Physics
Quantum Physics
While non-Hermitian (NH) topological phases and phenomena have been observed across various quantum systems, directly measuring NH topological invariants remains a significant challenge. In this study, we present a generic and unified framework for the direct measurement of various NH topological invariants in odd-dimensional systems through quench dynamics. We demonstrate that in one-dimensional (1D) NH systems with sublattice symmetry, the line-gap winding number and point-gap braiding degree can be extracted from the winding patterns of a dynamically constructed field based on post-quench spin textures. Specifically, line-gap topology is characterized by integer-valued winding, whereas point-gap complex-band braiding is revealed by half-integer or integer winding with abrupt jumps. We also extend our approach to higher-dimensional winding numbers and non-Bloch topological invariants under open-boundary conditions. Additionally, we propose a practical cold-atom setup to realize and detect 1D NH topological phases, showing that our dynamical measurement scheme is feasible in current experimental settings. This work paves the way for the direct measurement of NH topological invariants in quantum systems.
title Measuring Non-Hermitian Topological Invariants Directly from Quench Dynamics
topic Quantum Gases
Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2410.13241