Abstract:
In this talk, we discuss the dissipative quantum North-East-Center (NEC) model: a two-dimensional spin-1/2 lattice subject to chiral, kinetically constrained dissipation and coherent quantum interactions. This class of models combines kinetic constraints and chirality at the dissipative level, implementing local incoherent spin flips conditioned by an asymmetric majority-vote rule. Using a cluster mean-field approach, we determine the steady-state phase diagram of the NEC model under different Hamiltonians, consistently revealing the emergence of two distinct phases—bistable and normal—across all cases considered.
Finally, I will discuss the nonergodicity of the model in the bistable phase. Here, chiral dissipation induces the reabsorption of minority spin islands when they are surrounded by a large background of oppositely oriented spins. This reabsorption occurs at a constant velocity, independent of the island's size, a distinctive feature of the NEC model. We propose a phenomenological theory for the reabsorption dynamics to understand how the absorption velocity scales with system parameters, including quantum fluctuations at leading order.
Time & date: Wednesday 4th of June, 2025 at 11:30
Hosted by: Pietro Brighi
