Quantum Slow Relaxation and Metastability due to Dynamical Constraints

Understand

One of the general mechanisms that give rise to the slow cooperative relaxation characteristic of classical glasses is the presence of kinetic constraints in the dynamics.

• Here we show that dynamical constraints can similarly lead to slow thermalization and metastability in translationally invariant quantum many-body systems.
• We illustrate this general idea by considering two simple models: (i) a one-dimensional quantum analogue to classical constrained lattice gases where excitation hopping is constrained by the state of neighboring sites, mimicking excluded-volume interactions of dense fluids; and (ii) fully packed quantum dimers on the square lattice.
• Both models have a Rokhsar--Kivelson (RK) point at which kinetic and potential energy constants are equal.