Quantum Decoherence at Finite Temperatures

Abstract

We study measures of decoherence and thermalization of a quantum system $S$ in the presence of a quantum environment (bath) $E$. The whole system is prepared in a canonical thermal state at a finite temperature. Applying perturbation theory with respect to the system-environment coupling strength, we find that under common Hamiltonian symmetries, up to first order in the coupling strength it is sufficient to consider the uncoupled system to predict decoherence and thermalization measures of $S$. This decoupling allows closed form expressions for perturbative expansions for the measures of decoherence and thermalization in terms of the free energies of $S$ and of $E$. Numerical results for both coupled and decoupled systems with up to 40 quantum spins validate these findings.

5 pages, 3 figures

References in corpus (6)

• Typicality for Generalized Microcanonical Ensembles
• Decoherence in adiabatic quantum computation
• Thermal equilibration between two quantum systems
• Dynamics of thermalisation in small Hubbard-model systems
• Quantum Decoherence Scaling with Bath Size: Importance of Dynamics, Connectivity, and Randomness
• How ubiquitous are dragon segments in quantum transmission?

Cited by in corpus (6)

• Random State Technology
• Relaxation, thermalization and Markovian dynamics of two spins coupled to a spin bath
• Dynamics of open quantum spin systems: An assessment of the quantum master equation approach
• Initial-state-dependent thermalization in open qubits
• Finite thermal reservoirs and the canonical distribution
• Optimized Sampling of Mixed-State Observables