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TT: Fachverband Tiefe Temperaturen

TT 29: Many-Body Systems: Equilibration, Chaos, and Localization (joint session DY/TT)

TT 29.9: Talk

Tuesday, March 19, 2024, 11:45–12:00, A 151

Floquet-Anderson localization in the Thouless pump and how to avoid it — András Grabarits^{1, 2}, Attila Takács^{1, 3}, Ion Cosma Fulga^{4, 5}, and •János K. Asbóth^{1, 6} — ¹Dept of Theor. Physics, Budapest University of Technology and Economics — ²Dept of Physics and Materials Science, University of Luxembourg — ³Universite de Lorraine, CNRS, Nancy, France — ⁴Leibniz Institute for Solid State and Materials Research, IFW Dresden, — ⁵Wurzburg-Dresden Cluster of Excellence ct.qmat, 01062 Dresden — ⁶Wigner Research Centre for Physics, Budapest

We investigate numerically how onsite disorder affects conduction in the periodically driven Rice-Mele model, a prototypical realization of the Thouless pump, when run at finite period time T. We find that at any fixed period time and nonzero disorder, increasing the system size L to infinity always leads to a breakdown of the pump by Anderson localization of the Floquet states. In a properly defined thermodynamic limit, where L/T^θ is kept constant, Anderson localization can be avoided, and the charge pumped per cycle has a well-defined value (as long as the disorder is not too strong). The exponent θ is not universal, rather, depends on the disorder strength. Our findings are relevant for practical, experimental realizations of the Thouless pump, for studies investigating the nature of its current-carrying Floquet eigenstates, as well as the mechanism of the full breakdown of the pump, expected if the disorder exceeds a critical value.

Keywords: Topological phases; Thouless pump; Finite-size correction; Anderson localization