Unconventional geometric phase gates using two four-level rf-SQUIDs with cyclic population transfer in a cavity

Abstract

We propose a scheme for realizing two-qubit quantum phase gates via an unconventional geometric phase shift using two four-level superconducting artificial atoms with cyclic population transfer (broken symmetry) in a cavity. In this scheme, the logical gates' operation only involves the metastable states of each artificial atom. Moreover, under certain conditions, the atoms are disentangled with the cavity mode. Thus, the gate is insensitive to both the atomic spontaneous emission and the cavity decay.