title: Andreev level qubit.
abstract: We investigate the dynamics of a two-level Andreev bound state system in a transmissive quantum point contact embedded in an rf SQUID. Coherent coupling of the Andreev levels to the circulating supercurrent allows manipulation and readout of the level states. The two-level Hamiltonian for the Andreev levels is derived, and the effect of interaction with the quantum fluctuations of the induced flux is studied. We also consider an inductive coupling of qubits and discuss the relevant SQUID parameters for qubit operation and readout.
authors.affiliation: Department of Microelectronics and Nanoscience, Chalmers University of Technology and Göteborg University, S -41296 Göteborg, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Zazunov
authors.forename: V S
authors.initials: VS
authors.lastname: Shumeiko
authors.forename: E N
authors.initials: EN
authors.lastname: Bratus'
authors.forename: J
authors.initials: J
authors.lastname: Lantz
authors.forename: G
authors.initials: G
authors.lastname: Wendin