Changing the order of a dynamical phase transition through fluctuations in a quantum p-spin model
arXiv:2110.13524
Abstract
We study the non-equilibrium phase diagram of a fully-connected Ising -spin model, for generic , and investigate its robustness with respect to the inclusion of spin-wave fluctuations, resulting from a ferromagnetic, short-range spin interaction. In particular, we investigate the dynamics of the mean-field model after a quantum quench: we observe a new dynamical phase transition which is either first or second order depending on the even or odd parity of , in stark contrast with its thermal counterpart which is first order for all . The dynamical phase diagram is qualitatively modified by the fluctuations introduced by a short-range interaction which drive the system always towards various paramagnetic phases determined by the strength of time dependent fluctuations of the magnetization.
10+7 pages , 6+4 figures