Probing transport and slow relaxation in the mass-imbalanced Fermi-Hubbard model

TL;DR

This study investigates how constraints in the dynamics of a mass-imbalanced Fermi-Hubbard model lead to suppressed transport and slow relaxation, revealing complex non-equilibrium behavior in quantum many-body systems.

Contribution

The paper experimentally demonstrates constrained dynamics and slow relaxation in a mass-imbalanced Fermi-Hubbard model using ultracold atoms, highlighting the role of mass imbalance and interactions.

Findings

Suppressed transport observed with mass imbalance

Slow relaxation dynamics dependent on interactions

Potential for quantum simulators to explore unconventional relaxation

Abstract

Constraints in the dynamics of quantum many-body systems can dramatically alter transport properties and relaxation timescales even in the absence of static disorder. Here, we report on the observation of such constrained dynamics arising from the distinct mobility of two species in the one-dimensional mass-imbalanced Fermi-Hubbard model, realized with ultracold ytterbium atoms in a state-dependent optical lattice. By displacing the trap potential and monitoring the subsequent dynamical response of the system, we identify suppressed transport and slow relaxation with a strong dependence on the mass imbalance and interspecies interaction strength, consistent with eventual thermalization for long times. Our observations demonstrate the potential for quantum simulators to provide insights into unconventional relaxation dynamics arising from constraints.