Quantum Quenches and Relaxation Dynamics in the Thermodynamic Limit

TL;DR

This paper uses numerical linked cluster expansions to study quantum quench dynamics in one-dimensional lattice systems, revealing exponential relaxation and the quadratic scaling of relaxation rates with integrability breaking.

Contribution

It introduces NLCEs for analyzing quantum quenches, demonstrating their accuracy over exact diagonalization and characterizing relaxation behavior in nonintegrable regimes.

Findings

Local observables relax exponentially after quenches.

Relaxation rate scales quadratically with integrability breaking.

NLCEs outperform exact diagonalization in accuracy.

Abstract

We implement numerical linked cluster expansions (NLCEs) to study dynamics of lattice systems following quantum quenches, and focus on a hard-core boson model in one-dimensional lattices. We find that, in the nonintegrable regime and within the accessible times, local observables exhibit exponential relaxation. We determine the relaxation rate as one departs from the integrable point and show that it scales quadratically with the strength of the integrability breaking perturbation. We compare the NLCE results with those from exact diagonalization calculations on finite chains with periodic boundary conditions, and show that NLCEs are far more accurate.