2013/03/20 by Fernando C. Lombardo, Paula I. Villar · 1 citation
Physics and Astronomy · #cond-mat.other #quant-ph
paper · pdf · doi:10.1103/physreva.87.032338
8 pages, 8 figures. To appear in Phys. Rev. A
arxiv created 2013/03/20 · arxiv updated 2015/06/15
We describe the decoherence process induced on a two-level quantum system in direct interaction with a non-equilibrium environment. The non-equilibrium feature is represented by a non-stationary random function corresponding to the fluctuating transition frequency between two quantum states coupled to the surroundings. In this framework, we compute the decoherence factors which have a characteristic "dip" related to the initial phases of the bath modes. We therefore study different types of environments, namely ohmic and supra-ohmic. These environments present different decoherence time-scales than the thermal environment we used to study. As a consequence, we compute analytically and numerically the non-unitary geometric phase for the qubit in a quasi-cyclic evolution under the presence of these particular non-equilibrium environments. We show in which cases decoherence effects could, in principle, be controlled in order to perform a measurement of the geometric phase using standard procedures.