1304.6890 (Zi Cai et al.)

Algebraic and exponential decoherence in dissipative many-particle
systems    [PDF]

Zi Cai, Thomas Barthel

The interplay between dissipation and many-body quantum correlations gives rise to a wealth of novel phenomena. Here we investigate spin-1/2 chains with uniform local couplings to a Markovian environment using the time-dependent density matrix renormalization group (tDMRG). For the open XXZ model, we discover that the coherence decay is algebraic instead of exponential. This is due to a vanishing gap in the spectrum of the corresponding Liouville superoperator -- irrespective of the Hamiltonian gap -- and can be explained on the basis of a perturbative treatment. On the contrary, decoherence in the open transverse-field Ising model is found to be always exponential. In this case, the interactions can both facilitate and impede the environment-induced decoherence.

View original: http://arxiv.org/abs/1304.6890