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Friday, September 29, 2023
12:00 PM - 1:00 PM
East Bridge 114

IQIM Postdoctoral and Graduate Student Seminar

Probing localization properties of many-body Hamiltonians via an imaginary vector potential
Liam O'Brien, Refael Group,

Abstract: Identifying and measuring the "localization length'' in many-body systems in the vicinity of a many-body localization transition is difficult. Following Hatano and Nelson, a recent work (Heuben, White, Refael, PRB 103, 064201 (2021)) introduced an "imaginary vector potential'' to a disordered ring of interacting fermions, in order to define a many-body localization length (corresponding, in the non-interacting case, to the end-to-end Green's function of the hermitian system). We extend these results, by connecting this localization length to the length scale appearing in the avalanche model of delocalization. We use this connection to derive the distribution of the localization length at the MBL transition, finding good agreement with our numerical observations. Our results demonstrate how a localization length defined as such probes the localization of the underlying ring, without the need to explicitly construct the l-bits.

Lunch will be provided, following the talk, on the lawn north of the Bridge Building.

For more information, please contact Marcia Brown by phone at 626-395-4013 or by email at [email protected].