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QI: Fachverband Quanteninformation

QI 16: Concepts and Methods I

QI 16.5: Talk

Wednesday, March 8, 2023, 12:00–12:15, B302

Witnessing quantum non-Markovianity for high-entropy states using quasi-probability distributions — •Moritz Ferdinand Richter, Irene Ada Picatoste Fernández, and Heinz-Peter Breuer — Physikalisches Institut, Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany

Memory effects in the dynamics of open quantum systems can be characterized by the flow of information between the open systems and its environment [1]. Quantum non-Markovian dynamics features a flow of information from the environment back to the open system. A commonly used measure quantifying this information backflow is based on the evaluation of the trace distance between two quantum states evolving in time according to a family of quantum dynamical maps. Yet, the computation of this measure becomes increasingly demanding in case of continuous variable systems with increasing entropy of the states at hand. We present a witness for quantum non-Markovianity which is based on the Kolmogorov distance between quasi-probability distributions [2]. Furthermore, we show that this witness is particularly efficient in high-entropy scenarios, and apply it to the determination of non-Markovianity in quantum Brownian motion [3].

[1] H.-P. Breuer, E.-M. Laine, J. Piilo and B. Vacchini, Rev. Mod. Phys. 88, 021002 (2016).

[2] M. F. Richter, R. Wiedenmann and H.-P. Breuer, arXiv:2210.06058 [quant-ph].

[3] S. Einsiedler, A. Ketterer and H.-P. Breuer, Phys. Rev. A 102, 022228 (2020).