Motivated by recent experiments, which demonstrated lasing and cooling of the electromagnetic field in an electrical resonator coupled to a superconducting qubit, we study the phase coherence and diffusion of the system in the lasing state. We also discuss phase locking and synchronization induced by an additional {\sl ac} driving of the resonator. We extend earlier work to account for the strong qubit-resonator coupling and to include the effects of low-frequency qubit's noise. We show that the strong coupling may lead to a double peak structure of the spectrum, while the shape and width are determined to the low-frequency noise.
@article{arxiv.0807.4607,
title = {Phase diffusion and locking in single-qubit lasers},
author = {Stephan André and Valentina Brosco and Alexander Shnirman and Gerd Schön},
journal= {arXiv preprint arXiv:0807.4607},
year = {2009}
}
Comments
Revised version with a new section about the validity of the model when applied to describe experiments