$q$th-root non-Hermitian Floquet topological insulators
Longwen Zhou, Raditya Weda Bomantara, Shenlin Wu
SciPost Phys. 13, 015 (2022) · published 8 August 2022
- doi: 10.21468/SciPostPhys.13.2.015
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Abstract
Floquet phases of matter have attracted great attention due to their dynamical and topological nature that are unique to nonequilibrium settings. In this work, we introduce a generic way of taking any integer $q$th-root of the evolution operator $U$ that describes Floquet topological matter. We further apply our $q$th-rooting procedure to obtain $2^n$th- and $3^n$th-root first- and second-order non-Hermitian Floquet topological insulators (FTIs). There, we explicitly demonstrate the presence of multiple edge and corner modes at fractional quasienergies $±(0, 1,...2^n)π/2^n$ and $±(0, 1,..., 3^n)π/3^n$, whose numbers are highly controllable and capturable by the topological invariants of their parent systems. Notably, we observe non-Hermiticity induced fractional-quasienergy corner modes and the coexistence of non-Hermitian skin effect with fractional-quasienergy edge states. Our findings thus establish a framework of constructing an intriguing class of topological matter in Floquet open systems.
Cited by 21
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Longwen Zhou,
- 2 Raditya Weda Bomantara,
- 1 Shenlin Wu