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Q: Fachverband Quantenoptik und Photonik

Q 33: Open Quantum Systems

Q 33.2: Talk

Wednesday, March 13, 2024, 14:45–15:00, HS 1199

Landau-Zener dynamics in the presence of a non-Markovian reservoir — •Raphaël Menu and Giovanna Morigi — Universität des Saarlandes, Saarbrücken, Germany

We analyse the Landau-Zener dynamics of a qubit, which is simultaneously coupled to a dissipative auxiliary system. By tuning the coupling, the qubit dynamics ranges from a dephasing master equation to a strongly coupled qubit-auxiliary system, which is effectively a non-Markovian reservoir for the qubit. We determine the quantum trajectories in the different regimes . For each regime we analyse the distribution of each trajectory in terms of the time-dependent probability of a diabatic transitio. Depending on the strength of the coupling, we observe multipeaked configurations, which undergo transitions to narrow distributions. These transitions are signalled by a higher probability that a jump occurs. The behavior of the probability of a quantum jump as a function of the coupling and of the time of the sweep, in turn, allows us to shed light on the stages of the dynamics when the environment is detrimental and when instead it corrects diabatic transition. It shows, in particular, that memory effects can be beneficial. It further sheds light on the role of pausing in annealing and when it is advantageous.

Keywords: Adiabatic dynamics; Quantum trajectories; Non-Markovianity