Detecting non-Bloch topological invariants in quantum dynamics

TL;DR

This paper demonstrates the dynamic detection of non-Bloch topological invariants in non-Hermitian quantum systems using single-photon quantum walks, revealing their intrinsic nature and robustness against disorder.

Contribution

It introduces experimental methods to detect non-Bloch topological invariants dynamically in quantum walks, confirming their intrinsic properties in large systems.

Findings

Detection of non-Bloch invariants via biorthogonal chiral displacement

Robustness of detection against symmetry-preserving disorder

Consistency with theoretical predictions

Abstract

Non-Bloch topological invariants preserve the bulk-boundary correspondence in non-Hermitian topological systems, and are a key concept in the contemporary study of non-Hermitian topology. Here we report the dynamic detection of non-Bloch topological invariants in single-photon quantum walks, revealed through the biorthogonal chiral displacement, and crosschecked with the dynamic spin textures in the generalized quasimomentum-time domain following a quantum quench. Both detection schemes are robust against symmetry-preserving disorders, and yield consistent results with theoretical predictions. Our experiments are performed far away from any boundaries, and therefore underline non-Bloch topological invariants as intrinsic properties of the system that persist in the thermodynamic limit. Our work sheds new light on the experimental investigation of non-Hermitian topology.