1207.0726 (Juliana Restrepo et al.)

Decoherence induced by an ordered environment    [PDF]

Juliana Restrepo, S. Camalet, R. Chitra

To study the effect on the time evolution of a qubit, of an environment which undergoes a transition to an ordered phase, we consider a qubit weakly coupled to a standard BCS superconductor. We find that ordering in the superconducting bath generically leads to an unfavorable faster-than- exponential decay of the qubit coherence. On the other hand, a coupling to the non-ordered sector of the bath can result in a drastic reduction of the qubit decoherence. Since these behaviors are endemic to the ordered phase, qubits can serve as useful probes of phase transitions in their environment.

View original: http://arxiv.org/abs/1207.0726