Weak Coupling and Continuous Limits for Repeated Quantum Interactions
Attal, Stephane ; Joye, Alain
arXiv, 0501012 / Harvested from arXiv
We consider a quantum system in contact with a heat bath consisting in an infinite chain of identical sub-systems at thermal equilibrium at inverse temperature $\beta$. The time evolution is discrete and such that over each time step of duration $\tau$, the reference system is coupled to one new element of the chain only, by means of an interaction of strength $\lambda$. We consider three asymptotic regimes of the parameters $\lambda$ and $\tau$ for which the effective evolution of observables on the small system becomes continuous over suitable macroscopic time scales $T$ and whose generator can be computed: the weak coupling limit regime $\lambda\ra 0$, $\tau=1$, the regime $\tau\ra 0$, $\lambda^2\tau \ra 0$ and the critical case $\lambda^2\tau=1$, $\tau\ra 0$. The first two regimes are perturbative in nature and the effective generators they determine is such that a non-trivial invariant sub-algebra of observables naturally emerges. The third asymptotic regime goes beyond the perturbative regime and provides an effective dynamics governed by a general Lindblad generator naturally constructed from the interaction Hamiltonian. Conversely, this result shows that one can attach to any Lindblad generator a repeated quantum interactions model whose asymptotic effective evolution is generated by this Lindblad operator.
Publié le : 2005-01-06
Classification:  Mathematical Physics,  81Q99
@article{0501012,
     author = {Attal, Stephane and Joye, Alain},
     title = {Weak Coupling and Continuous Limits for Repeated Quantum Interactions},
     journal = {arXiv},
     volume = {2005},
     number = {0},
     year = {2005},
     language = {en},
     url = {http://dml.mathdoc.fr/item/0501012}
}
Attal, Stephane; Joye, Alain. Weak Coupling and Continuous Limits for Repeated Quantum Interactions. arXiv, Tome 2005 (2005) no. 0, . http://gdmltest.u-ga.fr/item/0501012/