Landau level subbands as a platform for many-body localization

Previous numerical results [1] have confirmed the theoretical argument [2] that many-body localization is not possible in a Landau level in the presence of interactions and arbitrary disorder. We examine the possibility of many-body localization in subbands (both topological and non-topological) derived from the lowest Landau level. In particular, we use two specific models – a suitably engineered flat band potential, and randomly placed point-like impurities, to create subbands into which we project the problem, including both ineractions and disorder. We use exact diagonalization to compute the level spacing ratio as a diagnostic of localization. The results show the absence of localization in topological subbands and the possibility of a finite-disorder many-body localization transition in non-topological subbands. This represents a novel setting for the study of many-body localization in one and two dimensions.

[1] S. D. Geraedts and R. N. Bhatt, Phys. Rev. B 95, 054303 (2017)
[2] R. Nandkishore and A. C. Potter, Phys. Rev. B 90, 195115 (2014)
[3] A. Krishna, M. Ippoliti and R. N. Bhatt, arXiv:1810.xxxxx (2018)