Sudden quench of harmonically trapped mass-imbalanced fermions

TL;DR

This study investigates how mass and particle number imbalances affect the dynamical evolution of two-component fermionic systems in a harmonic trap after a sudden interaction quench, revealing a strong dependence on these imbalances.

Contribution

It provides a detailed analysis of the impact of mass and particle number imbalance on the non-equilibrium dynamics of few-fermion systems following a quench.

Findings

Evolution stability depends on mass and particle number imbalance.

Dramatic effects observed in Loschmidt echo, density distributions, and entanglement entropy.

Results are relevant for experiments with small fermionic mixtures.

Abstract

Dynamical properties of two-component mass-imbalanced few-fermion systems confined in a one-dimensional harmonic trap following a sudden quench of interactions are studied. It is assumed that initially the system is prepared in the non-interacting ground state and then, after a sudden quench of interactions, the unitary evolution is governed by interacting many-body Hamiltonian. By careful analysis of the evolution of the Loschmidt echo, density distributions of the components, and entanglement entropy between them, the role of mass imbalance and particle number imbalance on the system's evolution stability are investigated. All the quantities studied manifest a dramatic dependence on the number of heavy and lighter fermions in each component at a given quench strength. The results may have implications for upcoming experiments on fermionic mixtures with a well-defined and small number of particles.