Nonthermal entanglement dynamics in a dipole-facilitated glassy model with disconnected subspaces

We construct a dipole-facilitated kinetic constraint to partition the Hilbert space into three disconnected subspaces, two of which are nonthermal and the other acts as an intrinsic thermal bath. The resulting glassy system freely oscillates in nonthermal subspaces, making the quantum entanglement perform like a substantial qubit. The spatially spreading entanglement, quantified by concurrence, fidelity and 2-Rényi entropy, is found to be spontaneously recovered which is absent in other reference models. Under low-frequency random flip noise, this reversible hydrodynamics of entanglement holds high fidelity and volume law, while at high frequency thermalization unusually occurs leading to a strange phase transition. Our work offers an elaborate space structure for realizing ergodicity breaking and controllable entanglement dynamics.