Abstract
In two dimensions, dephasing by a bath cuts off Anderson localization that would otherwise occur at any energy density for fermions with disorder. For an isolated system with short-range interactions, the system can be its own bath, exhibiting diffusive (non-Markovian) thermal density fluctuations. We recast the dephasing of weak localization due to a diffusive bath as a self-interacting polymer loop. We investigate the critical behavior of the loop in dimensions, and find a nontrivial fixed point corresponding to a temperature where the dephasing time diverges. Assuming that this fixed point survives to , we associate it with a possible instability of the ergodic phase. Our approach may open a new line of attack against the problem of the ergodic to many-body-localized phase transition in spatial dimensions.
- Received 23 October 2017
DOI:https://doi.org/10.1103/PhysRevLett.120.236601
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