Erlangen 2022 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 17: Quantum Optics (Miscellaneous) III
Q 17.7: Talk
Tuesday, March 15, 2022, 12:15–12:30, Q-H14
A remedy to finite coupling master equations for open quantum systems — •Becker Tobias1, Alexander Schnell1, Juzar Thingna2, and André Eckardt1 — 1Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany — 2Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon 34126, Republic of Korea
For the description of open quantum systems master equations are used that are derived perturbatively to some order of the system-bath coupling strength. The Bloch-Redfield master equation and all other first order expansions give an adequate description only in trivial order of the coupling strength that is for almost vanishing coupling. Attempts to increase the accuracy beyond the Bloch-Redfield equation must go beyond first order perturbation theory. However, for a wide range models, rigorous higher order expansions are hardly possible. We develop a master equation for finite coupling that is easily obtained within the Bloch-Redfield formalism. We benchmark our results against the exact solution of the damped harmonic oscillator that also features non-Markovian behaviour.