laboratoire pierre aigrain
électronique et photonique quantiques
laboratoire pierre aigrain

Seminar, November 30th 2015 (conf IV)

Lev B. Ioffe (LPTHE-Paris)
Puzzle of bad metals in Josephson junction arrays : experiment and theory

In the introduction I review the physics of the 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 chain display a dynamical transition to the many body localized state. This transition is preempted by the parametrically wide regime of non-ergodic behavior. 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 the experimental observation of these transitions.