We consider a two-level system, S2, coupled to a general n level system, Sn, via a random matrix. We derive an integral representation for the mean reduced density matrix p(t) of S2 in the limit n → ∞, and we identify a model of Sn which possesses some of the properties expected for macroscopic thermal reservoirs. In particular, it yields the Gibbs form for ρ (∞). We also consider an analog of the van Hove limit and obtain a master equation (Markov dynamics) for the evolution of ρ(t) on an appropriate time scale.
All Science Journal Classification (ASJC) codes
- Statistical and Nonlinear Physics
- Mathematical Physics
- Physics and Astronomy(all)