Localization and glassy dynamics of many-body quantum systems

Area of Science:

• Quantum physics
• Condensed matter physics
• Statistical mechanics

Background:

• Classical systems failing to explore configurational space can lead to aging and glass formation.
• Closed quantum systems may also cease exploring their entire Hilbert space, even from large initial superpositions.

Purpose of the Study:

• To investigate the out-of-equilibrium dynamics of strongly interacting lattice bosons.
• To identify the mechanisms behind the observed trapping in metastable states and lack of thermalization.

Main Methods:

• Numerical simulations of strongly interacting lattice bosons.
• Analysis of density excitations and their dynamics.
• Identification of dynamical arrest and inhomogeneous metastable states.

Main Results:

• Evidence of strongly interacting lattice bosons being trapped in extremely long-lived inhomogeneous metastable states when driven far from equilibrium.
• Identification of slowed-down incoherent density excitations, analogous to dynamical arrest near a glass transition, as the key feature.
• Demonstration that these long-lived inhomogeneities are responsible for the failure to thermalize in large systems.

Conclusions:

• The study reveals a novel mechanism for non-thermalizing dynamics in quantum systems.
• The findings suggest a quantum analogue to classical glass formation and aging.
• Experimental verification is proposed using trapped cold atoms to probe these out-of-equilibrium quantum dynamics.