Boson cavities: From electronic transport to quantum chaos

This is a 'mini-review' of some recent results on electron transport through two-level systems (e.g., double quantum dots) and simple mesoscopic scatterers (delta barrier), interacting with dissipative boson baths and single boson modes (phonons, photons). The relevant models (Spin-Boson system, Rabi-Hamiltonian) and their stationary properties (electron current, boson distribution) are investigated. For a single boson mode interacting with N two-level systems, the relation between quantum chaos and a quantum phase transition for N --> infinity is discussed.