Maniscalco, Sabrina

Thusday June 16, 2011
Time: 11:00
Place: HPF G 6
Host: Jonathan Home

Non-Markovian open quantum systems: Why should we care?

Sabrina Maniscalco
University of Turku, Finland

The theory of open quantum systems describes the dynamics of quantum systems interacting with their environment. This type of interaction is inevitable and leads to phenomena such as environment induced decoherence, responsible for the quantum to classical transition.

Understanding and modeling the dynamics of open quantum systems is important both for fundamental studies and for quantum technologies, since the latter ones rely on the persistence of quantum features such as entanglement and quantum superpositions.

Quantum optical systems generally interact with environments with quasi-flat frequency spectra. In these cases the dynamics is well described by Markovian master equations for the reduced density matrix of the open system. However, there exist physical systems, such as Bose-Einstein condensates, superconducting Josephson junctions, photonic crystals, etc., for which Markovian theories fail in the description of the correct system dynamics and of the reservoir memory effects.

While, in general, Markovian theories are well developed, non-Markovian theories are still peppered with fundamental open issues waiting to be understood and tested.

In my talk I will give a general overview of the theory of non-Markovian open quantum systems underlining the aspects that are currently at the center of a vivid debate, such as the very definition of non-Markovianity [1,2] and the non-Markovian extension of the quantum jumps approach [3]. To conclude I will briefly discuss a simple proposal to simulate a paradigmatic model of open quantum systems with trapped ions [4].

REFERENCES:
[1] Heinz-Peter Breuer, Elsi-Mari Laine, and Jyrki Piilo, Phys. Rev. Lett. 103, 210401 (2009).

[2] Ángel Rivas, Susana F. Huelga, and Martin B. Plenio, Phys. Rev. Lett. 105, 050403 (2010).

[3] Jyrki Piilo, Sabrina Maniscalco, Kari Härkönen, and Kalle-Antti Suominen
Phys. Rev. Lett. 100, 180402 (2008).

[4] Jyrki Piilo and Sabrina Maniscalco, Phys. Rev. A 74, 032303 (2006); S. Maniscalco, J. Piilo, F. Intravaia, F. Petruccione, and A. Messina, Phys. Rev. A 69, 052101 (2004).