Small quench dynamics as a probe for trapped ultracold atoms

Abstract

Finite systems of bosons and/or fermions described by the Hubbard model can be realized using ultracold atoms confined in optical lattices. The ground states of these systems often exhibit a coexistence of compressible superfluid and incompressible Mott insulating regimes. We analyze such systems by studying the out-of-equilibrium dynamics following a weak sudden quench of the trapping potential. In particular, we show how the temporal variance of the site occupations reveals the location of spatial boundaries between compressible and incompressible regions. The feasibility of this approach is demonstrated for several models using numerical simulations. We first consider integrable systems, hard-core bosons (spinless fermions) confined by a harmonic potential, where space separated Mott and superfluid phases coexist. Then, we analyze a nonintegrable system, a $J-V-V^{\prime }$ model with coexisting charge density wave and superfluid phases. We find that the temporal variance of the site occupations is a more effective measure than other standard indicators of phase boundaries such as a local compressibility. Based on these examples, we argue that analyzing temporal fluctuations is a valuable experimental tool for exploring phase boundaries in trapped atom systems.

References in corpus (11)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Thermalization and its mechanism for generic isolated quantum systems
• Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
• Foundation of Statistical Mechanics under experimentally realistic conditions
• Quantum critical scaling of the geometric tensors
• Quantum Monte Carlo simulations of confined bosonic atoms in optical lattices
• Local quantum criticality in confined fermions on optical lattices
• Quantum distillation and confinement of vacancies in a doublon sea
• Gaussian Equilibration
• Numerical simulations of strongly correlated fermions confined in 1D optical lattices
• Equilibration times in clean and noisy systems

Cited by in corpus (1)

• Theory of temporal fluctuations in isolated quantum systems