|Title||Increasing Spectroscopic Coherence Times of a DC SQUID Phase Qubit by Operating Deeper in the Potential Well|
|Publication Type||Journal Article|
|Year of Publication||2007|
|Authors||R. M. Lewis, S. K. Dutta, T. A. Palomaki, B. K. Cooper, A. J. Przybysz, A. J. Dragt, J. R. Anderson, C. J. Lobb, and F. C. Wellstood|
|Journal||IEEE Transactions on Applied Superconductivity|
|Keywords||2007, Multiple Fellows|
We present measurements of the spectroscopic coherence time, T2* of a Nb-AlOx-Nb dc SQUID phase qubit. T2* is calculated from the spectroscopic width of the |0rang to |1rang transition measured at 25 mK. We find that T2*increases at higher transition frequencies corresponding to measurements deeper in the potential well. The measured are consistent with root mean square current noise saturating at 4 nA.