Aarhus Universitets segl

CCQ Lunch Seminar - Frederik Nathan

Oplysninger om arrangementet


Onsdag 12. oktober 2022,  kl. 11:30 - 13:00



Title: Universal Lindblad equation for open quantum systems

Abstract: We develop a Markovian master equation in the Lindblad form that enables the efficient study of a wide range of open quantum many-body systems. The validity of the master equation is based entirely on properties of the bath and the system-bath coupling, without any requirements on the level structure within the system itself. The master equation is derived using a Markov approximation distinct from that used in earlier approaches. We provide a rigorous bound for the error induced by this Markov approximation; the error is controlled by a dimensionless combination of intrinsic correlation and relaxation timescales of the bath. Using the same timescales, we also establish rigorous error bounds on the steady-state obtained with our method. When expanded in terms of the timescales, our master equation is accurate on the same level of approximation as the Bloch-Redfield equation. In contrast to the Bloch-Redfield approach, our approach ensures preservation of the positivity of the density matrix, and can thus be solved robustly and efficiently using stochastic evolution of pure states (rather than density matrices).