Josephson-phase qubit without tunneling
M. H. S. Amin, Anatoly Yu. Smirnov, Alec Maassen van den Brink · Physical review. B, Condensed matter · 2003
We show that a complete set of one-bit gates can be realized by coupling the two logical states of a phase qubit to a third level (at higher energy) using microwave pulses. Thus, one can achieve coherent control without invoking any tunneling between the qubit levels. We propose two implementations, using rf-SQUIDs and d-wave Josephson junctions.