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arXiv · 1905.11308

Localization and interactions in topological and non-topological bands in two dimensions

Akshay Krishna·Matteo Ippoliti·R. N. Bhatt
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Abstract

A two-dimensional electron gas in a high magnetic field displays macroscopically degenerate Landau levels, which can be split into Hofstadter subbands by means of a weak periodic potential. By carefully engineering such a potential, one can precisely tune the number, bandwidths, bandgaps and Chern character of these subbands. This allows a detailed study of the interplay of disorder, interaction and topology in two dimensional systems. We first explore the physics of disorder and single-particle localization in subbands derived from the lowest Landau level, that nevertheless may have a topological nature different from that of the entire lowest Landau level. By projecting the Hamiltonian onto subbands of interest, we systematically explore the localization properties of single-particle eigenstates in the presence of quenched disorder. We then introduce electron-electron interactions and investigate the fate of many-body localization in subbands of varying topological character.

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Akshay Krishna, Matteo Ippoliti, R. N. Bhatt. 2019-05-29. Localization and interactions in topological and non-topological bands in two dimensions. https://doi.org/10.1103/physrevb.100.054202

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