Destruction of coherence in quantum systems with dissipation

Михаил Борисович Менский

E. T. Owen, Oliver Thomson Brown, Michael J. Hartmann

In quantum lattice systems with geometric frustration, particles cannot move coherently due to destructive interference between tunneling processes. Here we show that purely local, Markovian dissipation can induce mobility and long-range first-order coherence in frustrated lattice systems that is entirely generated by incoherent processes. Interactions reduce the coherences and mobility but do not destroy them. These effects are observable in experimental implementations of driven-dissipative lattices with a flat band and nonuniform dissipation.

Reinhold Egger, Hermann Grabert, Ulrich Weiß

The destruction of quantum coherence by environmental influences is investigated by taking the damped harmonic oscillator and the dissipative two-state system as prototypical examples. It is shown that the location of the coherent-incoherent transition depends to a large degree on the dynamical quantity under consideration.

Sudip Chakravarty

Malay Bandyopadhyay

With this work, I demonstrate the influence of a highly oscillating external field on the coherent tunneling of a quartic double-well potential. Extensive investigation on the tunneling rate of such a quantum system is made using the effective Hamiltonian formalism of (Rahav et al 2003 Phys. Rev. Lett. 91 110404; Rahav et al 2003 Phys. Rev. A 68 013820) for rapidly driven quantum systems. The present model explains the phenomena of chaos assisted tunneling (CAT), i.e. the enhancement of the tunneling rate. The two-level system (TLS) successfully explains the coherent destruction of tunneling (CDT). The effect of dissipation on CAT and CDT are also demonstrated in the present paper.

吉隆 谷村