Multicritical behavior in dissipative Ising models
  We analyze theoretically the many-body dynamics of a dissipative Ising model in a transverse field using a variational approach. We find that the steady state phase diagram is substantially modified compared to its equilibrium counterpart, including the appearance of a multicritical point belonging to a different universality class. Building on our variational analysis, we establish a field-theoretical treatment corresponding to a dissipative variant of a Ginzburg-Landau theory, which allows us to compute the upper critical dimension of the system. Finally, we present a possible experimental realization of the dissipative Ising model using ultracold Rydberg gases. 
Vincent R. Overbeck, Mohammad F. Maghrebi, Alexey V. Gorshkov, Hendrik   Weimer
cond-mat.stat-mech physics.atom-ph quant-ph