Delocalized Glassy Dynamics and Many Body Localisation
MAY 17, 2017 | 11:00 AM TO 12:30 PM
The Graduate Center
365 Fifth Avenue
May 17, 2017: 11:00 AM-12:30 PM
Initiative for the Theoretical Sciences and PhD Program in Physics
Seminar will take place in Room 5209.
Speaker: Giulio Biroli (CEA, Paris)
Research activity on quenched disorder, interactions and quantum fluctuations boomed recently after the discovery of the Many-Body Localization (MBL) transition. One of the most surprising results is that even the delocalised phase is unusual. Before the MBL transition, in a wide range of parameters, transport appears to be sub-diffusive and out-of equilibrium relaxation toward thermal equilibrium is slow and
power-law like with exponents that gradually approach zero at the transition. Several works explained this behavior in terms of Griffiths regions, i.e. rare inclusions of the localised phase which impede transport and relaxation. In this talk, using a toy model of MBL, I will present a complementary explanation directly based on quantum dynamics in Fock-space and relate it to glassy (or non-ergodic)
features of the delocalised phase.