Tunable coupling of qubits: Nonadiabatic corrections Carsten Hutter, Alexander Shnirman, Yuriy Makhlin and Gerd Schön Europhys. Lett., 74 6 (2006) 1088-1094 Published online: 17 May 2006 DOI: 10.1209/epl/i2006-10054-4