Nonlinear quantum Langevin equations for bosonic modes in solid-state systems
Manninen, Juuso; Agasti, Souvik; Massel, Francesco (2017). Nonlinear quantum Langevin equations for bosonic modes in solid-state systems. Physical Review A, 96 (6), 063830. DOI: 10.1103/PhysRevA.96.063830
Published inPhysical Review A
© 2017 American Physical Society. Published in this repository with the kind permission of the publisher.
Based on the experimental evidence that impurities contribute to the dissipation properties of solid-state open quantum systems, we provide here a description in terms of nonlinear quantum Langevin equations of the role played by two-level systems in the dynamics of a bosonic degree of freedom. Our starting point is represented by the description of the system-environment coupling in terms of coupling to two separate reservoirs, modeling the interaction with external bosonic modes and two-level systems, respectively. Furthermore, we show how this model represents a specific example of a class of open quantum systems that can be described by nonlinear quantum Langevin equations. Our analysis offers a potential explanation of the parametric effects recently observed in circuit-QED cavity optomechanics experiments.