Mixed-Order Symmetry-Breaking Quantum Phase Transition Far from Equilibrium.
Puel, T O;Chesi, Stefano;Kirchner, S;Ribeiro, P;
physical review letters2019Vol. 122pp. 235701
183
puel2019mixedorderphysical
Abstract
We study the current-carrying steady state of a transverse field Ising chain coupled to magnetic thermal reservoirs and obtain the nonequilibrium phase diagram as a function of the magnetization potential of the reservoirs. Upon increasing the magnetization bias we observe a discontinuous jump of the magnetic order parameter that coincides with a divergence of the correlation length. For steady states with a nonvanishing conductance, the entanglement entropy at zero temperature displays a bias dependent logarithmic correction that violates the area law and differs from the well-known equilibrium case. Our findings show that out-of-equilibrium conditions allow for novel critical phenomena not possible at equilibrium.