Rabi oscillations of a qubit coupled to a two-level system Y. M. Galperin, D. V. Shantsev, J. Bergli and B. L. Altshuler Europhys. Lett., 71 1 (2005) 21-27 Published online: 27 May 2005 DOI: 10.1209/epl/i2005-10053-y