%0 Journal Article
%T Microwave-Induced Cooling of a Superconducting Qubit
%A S. O. Valenzuela
%A W. D. Oliver
%A D. M. Berns
%A K. K. Berggren
%A L. S. Levitov
%A T. P. Orlando
%J Physics
%D 2007
%I arXiv
%R 10.1126/science.1134008
%X We demonstrated microwave-induced cooling in a superconducting flux qubit. The thermal population in the first-excited state of the qubit is driven to a higher-excited state by way of a sideband transition. Subsequent relaxation into the ground state results in cooling. Effective temperatures as low as Teff~ 3 millikelvin are achieved for bath temperatures Tbath = 30 - 400 millikelvin, a cooling factor between 10 and 100. This demonstration provides an analog to optical cooling of trapped ions and atoms and is generalizable to other solid-state quantum systems. Active cooling of qubits, applied to quantum information science, provides a means for qubit-state preparation with improved fidelity and for suppressing decoherence in multi-qubit systems.
%U http://arxiv.org/abs/cond-mat/0702190v1