Proposal for realizing anomalous Floquet insulators via Chern band annihilation

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Dokumenter

  • Carolyn Zhang
  • Tobias Holder
  • Netanel H. Lindner
  • Mark S. Rudner
  • Erez Berg

Two-dimensional periodically driven systems can host an unconventional topological phase unattainable for equilibrium systems, termed the Anomalous Floquet-Anderson insulator (AFAI). The AFAI features a quasi-energy spectrum with chiral edge modes and a fully localized bulk, leading to non-adiabatic but quantized charge pumping. Here, we show how such a Floquet phase can be realized in a driven, disordered Quantum Anomalous Hall insulator, which is assumed to have two critical energies where the localization length diverges, carrying states with opposite Chern numbers. Driving the system at a frequency close to resonance between these two energies localizes the critical states and annihilates the Chern bands, giving rise to an AFAI phase. We exemplify this principle by studying a model for a driven, magnetically doped topological insulator film, where the annihilation of the Chern bands and the formation of the AFAI phase is demonstrated using the rotating wave approximation. This is complemented by a scaling analysis of the localization length for two copies of a quantum Hall network model with a tunable coupling between them. We find that by tuning the frequency of the driving close to resonance, the driving strength required to stabilize the AFAI phase can be made arbitrarily small.

OriginalsprogEngelsk
Artikelnummer124
TidsskriftSciPost Physics
Vol/bind12
Udgave nummer4
Antal sider33
ISSN2542-4653
DOI
StatusUdgivet - 11 apr. 2022

Bibliografisk note

Funding Information:
We are grateful to M. Levin, A. Altland and S. Sondhi for helpful discussions. CZ is supported by the Kadanoff Center for Theoretical Physics at the University of Chicago and the National Science Foundation Graduate Research Fellowship under Grant No. 1746045. NL acknowledges support from the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 639172), and from the Israeli Center of Research Excellence (I-CORE) “Circle of Light”. EB and MR acknowledge support from CRC 183 of the Deutsche Forschungsgemeinschaft (Project A01). This work was supported by a research grant from Irving and Cherna Moskowitz. MR gratefully acknowledges the support of the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (Grant Agreement No. 678862), and the Villum Foundation.

Publisher Copyright:
Copyright © C. Zhang et al.

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