title: Spontaneous formation of a pi soliton in a superconducting wire with an odd number of electrons.
abstract: We consider a one-dimensional superconducting wire where the total number of electrons can be controlled in the Coulomb blockade regime. We predict that a pi soliton (kink) will spontaneously form in the system when the number of electrons is odd, because this configuration has a lower energy. If the wire with an odd number of electrons is closed in a ring, the phase difference on the two sides of the soliton will generate a supercurrent detectable by a SQUID. The two degenerate states with the current flowing clockwise or counterclockwise can be utilized as a qubit.
authors.affiliation: Department of Physics and Center for Superconductivity Research, University of Maryland, College Park, Maryland 20742-4111, USA.
authors.forename: Hyok-Jon
authors.initials: HJ
authors.lastname: Kwon
authors.forename: Victor M
authors.initials: VM
authors.lastname: Yakovenko