Open quantum system

In physics, an open quantum system is a quantum-mechanical system which interacts with an external quantum system, the environment. In reality, no quantum system is completely isolated from its surroundings, so every quantum system is open to some extent, causing dissipation in the quantum system. Techniques developed in the context of open quantum systems have proven powerful in fields such as quantum optics, quantum measurement theory, quantum statistical mechanics, quantum information science, quantum cosmology and semi-classical approximations.

The environment we wish to model as part of our open quantum system is typically very large, making exact solutions impossible to calculate. However, by making key approximations it is possible to find out how the quantum system behaves in the presence of the environment. There are two approximations commonly made in the field of open quantum systems: the Born approximation and the Markov approximation. The Born approximation assumes that the system-bath coupling is relatively weak, and the bath is very large, so that the bath is negligibly affected by the system. The Markov approximation assumes that the bath has no memory of past events.^[1]

See also

• Learning materials related to Open Quantum Systems at Wikiversity
• Lindblad equation
• Markov property
• Master equation

References

• Accardi, Luigi; Lu, Yun Gang; Volovich, I.V. (2002). Quantum Theory and Its Stochastic Limit. New York: Springer Verlag. ISBN 978-3-5404-1928-0. 
• Alicki, Robert; Lendi, Karl (1987). Quantum Dynamical Semigroups and Applications. Berlin: Springer Verlag. ISBN 978-0-3871-8276-6. 
• Attal, Stéphane; Joye, Alain; Pillet, Claude-Alain (2006). Open Quantum Systems II: The Markovian Approach. Springer. ISBN 978-3-5403-0992-5. 
• Davies, Edward Brian (1976). Quantum Theory of Open Systems. London: Academic Press. ISBN 978-0-12-206150-9. 
• Ingarden, Roman S.; Kossakowski, A.; Ohya, M. (1997). Information Dynamics and Open Systems: Classical and Quantum Approach. New York: Springer Verlag. ISBN 978-0-7923-4473-5. 
• Lindblad, G. (1983). Non-Equilibrium Entropy and Irreversibility. Dordrecht: Delta Reidel. ISBN 1-4020-0320-X. 
• Okolowicz, J.; Płoszajczak, M.; Nazarewicz, W. (2012). "On the Origin of Nuclear Clustering". Progress of Theoretical Physics Supplement. 196: 230. arXiv:1202.6290. Bibcode:2012PThPS.196..230O. doi:10.1143/PTPS.196.230. 
• Tarasov, Vasily E. (2008). Quantum Mechanics of Non-Hamiltonian and Dissipative Systems. Amsterdam, Boston, London, New York: Elsevier Science. ISBN 978-0-0805-5971-1. 
• Weiss, Ulrich (2012). Quantum Dissipative Systems (4th ed.). World Scientific. ISBN 978-9-8143-7491-0. 
• Wiseman, Howard M.; Milburn, Gerard J. (2010). Quantum Measurement and Control. Cambridge University Press. ISBN 9780521804424.