Random Interactions
Collective far-from-equilibrium behavior in quantum gases: Open and Closed Systems
by Dr. Manas Kulkarni (Princeton University)
Wednesday, August 20, 2014
from
to
(Asia/Kolkata)
at Colaba Campus ( A304 )
at Colaba Campus ( A304 )
Description |
In this presentation, I will discuss non-equilibrium aspects of Bosonic atoms in two different scenarios, (i) when it behaves as an isolated quantum system out-of equilibrium and (ii) when it is an open quantum system in which the Bose gas is driven and coupled to photons inside a leaky cavity. I will first discuss the nonlinear dynamics of an isolated Bose gas. In particular, I will discuss the physics and universality arising upon quenching an excited state corresponding to a collective solitonic excitation. I will show that, in this case, the Bose gas falls into the universality class described by the Korteweg-de Vries equation [1]. I will also discuss results on dynamical critical phenomenon of a 1D Bose gas and show its strong connection to the Kardar-Parisi-Zhang universality class [2,3]. I will then discuss an open quantum system consisting of a Bose gas placed in an optical cavity and pumped by a laser [4]. This can be mapped to a non-local Gross-Pitaeveski equation and also to the Caldeira-Leggett model of quantum dissipation. I will describe the non-trivial dissipative properties near the critical point of an open quantum phase transition [5], which explained recent surprising experimental findings. I will also describe the rich dynamics of this driven-dissipative quantum gas and show this to be deeply rooted in the theory of non-Hermitian physics and the pseudo-spectrum of this open quantum system [6]. (1) M. Kulkarni, A. G. Abanov, Phys. Rev. A, 86, 033614; F. Franchini, A. Gromov , M. Kulkarni, A. Trombettoni, (2014) (2) M. Kulkarni, D. A. Huse, H. Spohn (2014); M. Kulkarni, A. Lamacraft, Phys. R ev. A 88, 021603, Rapid Communication (3) M. Kulkarni, Journal of Statistical Physics (invited article, 2014) (4) R. Mottl et al, Science 336, 1570 (2012); K. Baumann et al, Nature 464, 1301 (2010) (5) M. Kulkarni, B. Oztop and H. E. Tureci, Phys. Rev. Lett, 111, 220408 (6) M. Kulkarni, K. G. Makris, H. E. Tureci (2014) |