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.
Cite
@article{arxiv.cond-mat/0702190,
title = {Microwave-Induced Cooling of a Superconducting Qubit},
author = {S. O. Valenzuela and W. D. Oliver and D. M. Berns and K. K. Berggren and L. S. Levitov and T. P. Orlando},
journal= {arXiv preprint arXiv:cond-mat/0702190},
year = {2008}
}
Comments
Comments Article plus Supplementary Online Material. 19 pages, 6 figures