Hendrik Bluhm, Nicholas C. Koshnick, Martin E. Huber, Kathryn A. Moler
Published 2006-08-11, updated 2006-12-16Version 2
The magnetic response and fluxoid transitions of superconducting aluminum rings of various sizes, deposited under conditions likely to generate a layered structure, show good agreement with a two-order-parameter Ginzburg-Landau model. For intermediate couplings, we find metastable states that have different phase winding numbers around the ring in each of the two order parameters. Those states, previously theoretically predicted, are analogous to fractional vortices in singly connected samples with two-order-parameter superconductivity. Larger coupling locks the relative phase so that the two order parameters are only manifest in the temperature dependence of the response. With increasing proximitization, this signature gradually disappears.
Comments: 4 pages, 3 figures. See http://stanford.edu/group/moler/publications.html for the auxiliary document describing some of the analysis procedures (Ref. 25). Journal version. Rewritten introduction. Some sentences added, some removed, changes in wording. Corrected a few errors, updated references
Journal: Phys. Rev. Lett. 97, 237002 (2006)
Transport through (Ga,Mn)As nanoislands: Coulomb-blockade and temperature dependence of the conductance
Temperature dependence and mechanism of electrically detected ESR at the n=1 filling factor of a two-dimensional electron system in GaAs quantum wells
Magnetic Response in a Zigzag Carbon Nanotube
