Real-space topological invariant for time-quasiperiodic Majorana modes

Abstract

Defining topological invariants in systems with dense energy spectrum is inherently challenging due to the absence of gaps. Here, the authors define a topological invariant for time quasiperiodically driven superconducting systems using spectral localizers, a recently developed tool for probing real-space topology. The invariant is shown to identify the number and quasienergy of quasiperiodic Majorana modes hosted by the system. Drawing insights from non-Hermitian physics, the authors also establish a criterion and provide a physical interpretation for spectral localizers, thereby widening their applicability.

Topics & Concepts