Regensburg 2007 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Quantum Coherence and Quantum Information Systems I
TT 3.7: Vortrag
Montag, 26. März 2007, 11:30–11:45, H20
One-qubit laser and cooler — Julian Hauss1, •Carsten Hutter1,2, Arkady Fedorov1, Alexander Shnirman1, and Gerd Schön1 — 1Institut für Theoretische Festkörperphysik, Universität Karlsruhe, D-76128 Karlsruhe, Germany — 2Department of Physics, Stockholm University, AlbaNova University Center, SE-10961 Stockholm, Sweden
We consider a setup performing Rabi spectroscopy of a superconducting qubit. The system consists of a slow electromagnetic or nano-mechanical oscillator coupled to a resonantly driven superconducting qubit. When the Rabi frequency of the qubit coincides with the eigenfrequency of the oscillator the latter can be driven into a strongly non-equilibrium state. Experiments of this type have recently been performed [1].
We find that by introducing detuning in the driving of the qubit one can create a population inversion at the Rabi frequency and this can lead to a “lasing” behavior of the qubit-oscillator system. In particular we consider a situation when the qubit is kept at its symmetry point where the decoherence due to 1/f noise is minimal. Then the coupling to the oscillator is quadratic and the system realizes a “single-atom-two-photon laser”.
[1] E. Il’ichev et al., Phys. Rev. Lett. 91, 097906 (2003)