Asymmetry Amplificaton by a Nonadiabatic Passage through a Critical Point

We propose and solve a minimal model of dynamic passage through a quantum second order phase transition in the presence of weak symmetry breaking interactions and no dissipation. The evolution eventually leads to a highly asymmetric state, no matter how weak the symmetry breaking term is. This suggests a potential mechanism for strong asymmetry in the production of particles with almost identical characteristics. The model's integrability also allows us to obtain exact Kibble-Zurek exponents for the scaling of the number of nonadiabatic excitations.