Non-equilibrium quantum probing through linear response

Abstract

The formalism of linear response theory can be extended to encompass physical situations where an open quantum system evolves towards a non-equilibrium steady-state. Here, we use the framework put forward by Konopik and Lutz [Phys. Rev. Research {\bf 1}, 033156 (2019)] to go beyond unitary perturbations of the dynamics. Considering an open system comprised of two coupled quantum harmonic oscillators, we study the system's response to unitary perturbations, affecting the Hamiltonian dynamics, as well as non-unitary perturbations, affecting the properties of the environment, e.g., its temperature and squeezing. We show that linear response, combined with a quantum probing approach, can effectively provide valuable quantitative information about the perturbation and characteristics of the environment, even in cases of non-unitary dynamics.

8 + 4 pages, 7 figures, RevTeX4-2 Close to published version in Phys. Rev. Research

References in corpus (4)

• Optomechanical entanglement between a movable mirror and a cavity field
• Fluctuation-Dissipation: Response Theory in Statistical Physics
• Individual quantum probes for optimal thermometry
• An update on nonequilibrium linear response

Cited by in corpus (4)

• Asymmetries of thermal processes in open quantum systems
• Non-Markovian to Markovian decay in structured environments with correlated disorder
• Non-equilibrium thermodynamics of gravitational objective-collapse models
• Open quantum systems beyond equilibrium: Lindblad equation and path integral molecular dynamics