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Thursday, July 15, 2010
12:30 PM - 2:00 PM
T-DO Conference Room - TA-03 Bldg 0123 Room 121

Quantum Lunch

O(N) symmetry-breaking quantum quench -- defect creation and scaling

Michael Uhlmann
Department of Physics and Astronomy, University of British Columbia

The rapid sweep through a symmetry-breaking second-order quantum phase transition entails fascinating non-equilibrium phenomena. Quantum fluctuations become unstable and start growing exponentially; the initial symmetry is spontaneously broken. Different realizations of this symmetry breaking will be chosen in causally disconnected spatial regions leading to the development of order parameter domains. If the final phase permits topological defects, e.g., vortices in two dimensions, they will generally be created by a quantum version of the Kibble-Zurek mechanism. In this talk, I will discuss the O(N) breaking quantum quench of an N dimensional vector field in N spatial dimensions. The scaling behavior of the net winding number with system size and the full statistics will be derived. Special emphasis is laid on the N = 2 case, as this can be realized in spinor Bose-Einstein condensates [L. E. Saddler et al., Nature (London) 443, 312].

Host: Wojciech Zurek