Events at Physics

<< Fall 2015 Spring 2016 Summer 2016 >>
Subscribe your calendar or receive email announcements of events
Condensed Matter Theory Group Seminar
Non-ergodicity in many body systems and the phase diagram of Josephson junction chains
Date: Monday, April 11th
Time: 10:00 am
Place: 5280 Chamberlin Hall
Speaker: Lev Ioffe, Rutgers
Abstract: At very high disorder a generic closed quantum systems becomes completely localized. I argue that this (many body) localization is preempted by a wide regime of non-ergodic behavior that displays a number of unusual properties. A good system to study these effects are Josephson junction arrays in a somewhat unusual regime.
I review the physics of Josephson arrays and the general problem of the superconductor-insulator transition in these structures. In the main part of the talk I will focus on the novel phases appearing in one-dimensional Josephson junction chains at relatively high temperatures. I will argue that these phases are robust with respect to the presence of the ubiquitous random charges and thus allow experimental observation. I show that at finite temperatures both ordered and disordered chains display a dynamical transition to the many body localized state. While resistivity is strictly infinite in the many body localized state, it is exponentially large in the intermediate non-ergodic bad metal. I will discuss the possibility of experimental observation of these transitions.
Host: Robert Mcdermott
Add this event to your calendar