Kavli Affiliate: Long Zhang
| First 5 Authors: Xiao-Dong Lin, Long Zhang, , ,
| Summary:
The accurate determination of non-Hermitian (NH) topological invariants plays
a central role in the study of NH topological phases. In this work, we propose
a general framework for directly measuring NH topological invariants in
even-dimensional systems through quench dynamics. Our approach hinges on
constructing an auxiliary Hermitian matrix topologically equivalent to the
original NH Hamiltonian, enabling topological characterization via
reduced-dimensional momentum subspaces called band inversion surfaces (BISs). A
key insight lies in the emergence of chiral symmetry in the NH Hamiltonian
specifically on BISs — a critical property that allows extension of the
dynamical characterization scheme previously developed for odd-dimensional NH
systems with chiral or sublattice symmetry [Lin et al., Phys. Rev. Res. 7,
L012060 (2025)]. We show that NH topological invariants can be extracted from
the winding patterns of a dynamical field constructed from post-quench spin
textures on BISs. We demonstrate our approach through a detailed analysis of NH
Chern insulators and then extend the framework to higher even-dimensional
systems by introducing second-order BISs for characterization. This work
establishes an experimentally accessible protocol for detecting NH topological
invariants in quantum platforms.
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