DPG Phi
Verhandlungen
Verhandlungen
DPG

Regensburg 2010 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 23: TR: Quantum Coherence and Quantum Information Systems 2

TT 23.5: Talk

Wednesday, March 24, 2010, 15:15–15:30, H18

Spectral properties of single-qubit lasers — •Stephan André1,2, Valentina Brosco3, Alexander Shnirman2,4, and Gerd Schön1,21Institut für Theoretische Festkörperphysik, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany — 2DFG Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany — 3Dipartimento di Fisica, Università "La Sapienza", P.le A. Moro 2, 00185 Roma, Italy — 4Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany

Recent experiments demonstrated lasing and cooling of the electromagnetic field in an electrical resonator coupled to a superconducting qubit [1]. In this work, we theoretically investigate the spectral properties of single-qubit lasers by numerically solving the full Liouville equation for the density matrix. We extend the usual quantum optics description to acccount for strong qubit-resonator coupling and to include the effects of low-frequency noise.

We present results for the linewidth and the lineshape of the emission spectrum. We find that the linewidth grows with the qubit-resonator coupling strength beyond the lasing transition, thus deteriorating the lasing state [2]. Our results also show that quantum correlations have a significant effect on the spectral properties and that low-frequency noise might explain the shape and width of the emission spectrum observed in the experiment.

[1] O. Astafiev et al., Nature 449, 588 (2007)

[2] S. André et al., arXiv:0908.4227 (2009)

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2010 > Regensburg