Keldysh green function approach to a nonequilibrium phase transition of Lipkin-Meshkov-Glick Model

Seminar über Theoretische Festkörperphysik

Vortragender:

Dr. Changwoo Lee

Datum:

31.10.2016 14:00

Ort:

Raum 10.01, Geb. 30.23 (Physikhochhaus), Campus Süd

Zugehörigkeit:

Korea Institute for Advanced Study, Seoul, Korea

Gastgeber:

Dr. Changhyoup Lee

Abstract

Keldysh's brilliant idea using a closed time contour has led to one of the most efficient analytical tools to describe non-equilibrium dynamics of condensed matter, atomic, and optical systems. It is based on real-time field theory and hence does not need the Wick rotation. It can also compare and hence unify the equilibrium and non-equilibrium descriptions, and in some cases when their universality classes coincide, make a possible mapping of the latter to the former. In this talk, a quantum optical realization of the dissipative Lipkin-Meshkov-Glick Model is reviewed and it will be shown that its quantum phase transition can be well (and more easily) described via the Keldysh formalism. Furthermore, some universal features of the Markovian dissipative dynamics and the mapping to the thermal equilibrium system will also be discussed.