Models of many-body quantum systems are often based on an assumption that the system is perfectly isolated from its environment, but this is not always true for their counterparts in the real world. For example, a quantum computer may work flawlessly on paper, but any realisation will have to deal with environmental noise that can destroy the carefully prepared quantum superpositions on which the computer relies.
Systems that are not completely isolated from their environment are known as dissipative or open systems. The environment can be modeled as a quantum bath that is coupled to the system, similar to a heat bath from the theory of thermodynamics. Although the model does not keep track of everything that happens inside the quantum bath, it provides a probabilistic description of the effect that the bath has on the system. In other words, it tells you the chance that the environment will have disturbed the system in a certain way at any point in time.
Moos van Caspel studies dissipation in a number of one-dimensional models from condensed matter physics.
M.T. van Caspel: Symmetries and Topology in Quantum Baths.
Prof. dr. J.S. Caux
Dr V. Gritsev
Dr D. Schuricht