Quantum collision models

Giorno 27 gennaio 2020, con inizio alle ore 9:00, presso l'Aula D del DFA, su invito dei Professori Giuseppe Falci e Alessandro Ridolfo, il Dr Francesco Ciccarello (NEST, Istituto Nanoscienze-CNR & University of Palermo, Italy) terrà un seminario/lezione dal titolo: Quantum collision models: a tutorial.

Tutti gli interessati sono invitati a partecipare.

Abstract.

A collision model (or repeated-interactions model or conveyor-belt model) is a simple theoretical framework in which a system S undergoes successive interactions (“collisions”) with the subunits of a large environment [1-4]. Currently, quantum collision models are being used more and more in research areas such as non-Markovian quantum dynamics [5], quantum thermodynamics (where they became a standard tool by now) [6], quantum optics [7] and, in some respects, even quantum gravity [8].

This tutorial aims at introducing some basic concepts of Markovian quantum collision models. Given the remarkable simplicity of collision models and their intimate connection with a number of central concepts/tools in open quantum systems theory - such as quantum maps, the Stinespring dilation theorem, the Lindblad master equation and quantum trajectories - the tutorial can also be seen as a pedagogical, short introduction to open quantum systems theory itself.

The standard model of quantum optics treating the field as a white-noise bosonic bath is an important microscopic scenario which can be exactly mapped into a collision model. We will show this in some detail and use the same framework for the classroom demonstrations (second seminar). These will illustrate how spontaneous/stimulated decay and optical Bloch equations can be derived ab initio from a fully quantum atom-field model through a collision-model approach.

Required background:

• elementary quantum mechanics;
• a minimum acquaintance with atom-field interaction when the field is quantized;
• a minimum familiarity with the density-matrix language would help, although we will briefly review it in the beginning.

References:

1. J. Rau, Phys. Rev. 129, 1880 (1963).
2. C. M. Caves and J. G. Milburn, Phys. Rev. A 36, 5543 (1987).
3. T. A. Brun, Am. J. Phys. 70, 719 (2002).
4. V. Scarani M. Ziman, P. Stelmachovic, N. Gisin, and V. Buzek, Phys. Rev. Lett. 88, 097905 (2002).
5. F. Ciccarello, G. M. Palma, and V. Giovannetti, Phys. Rev. A 87, 040103(R) (2013).
6. P. Strasberg, G. Schaller, T. Brandes, and M. Esposito, Phys. Rev. X 7, 021003 (2017).
7. A. Grimsmo, Phys. Rev. Lett. 115, 060402 (2015); H. Pichler and P. Zoller, Phys. Rev. Lett 116,093601(2016); F. Ciccarello, Quantum Meas. Quantum Metrol. 4,53 (2017); J. A. Gross, C. M. Caves, G. J. Milburn, and J. Combes, Quantum Sci. Technol. 3, 024005 (2018).
8. N. Altamirano, P. Corona-Ugalde, R. Mann, and M. A. Zych, New J. Phys. 19, 013035 (2017).