University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Tuesday, May 3rd 2016
4:30 pm:
CM Journal Club in PAN 120
Speaker: Peter Orth
Subject: Universal post-quench coarsening and quantum aging at a quantum critical point

I will discuss non-equilibrium dynamics of an interacting bosonic quantum field theory following a rapid change of a parameter. Such a quench protocol was realized recently in a number of cold-atom experiments and corresponds to a fast change of parameters such as magnetic field or pressure in a solid-state system. I first introduce basic features of non-equilibrium and the non-equilibrium Keldysh notation for a parameter quench in a non-interacting system, which corresponds to rapidly changing the quadratic potential of a harmonic oscillator. Then, I will discuss the effect of quartic interactions within a large-N approach. I show that if a system is tuned to close proximity of a critical point, the non-equilibrium dynamics shows universal features characterized by a new scaling exponent.

This is based on work published in

P. Gagel, PPO, J. Schmalian, Phys. Rev. Lett. 113, 220401 (2014)
P. Gagel, PPO, J. Schmalian, Phys. Rev. B 92, 115121 (2015)

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