1,935 research outputs found
Hybridization and interference effects for localized superconducting states in strong magnetic field
Within the Ginzburg-Landau model we study the critical field and temperature
enhancement for crossing superconducting channels formed either along the
sample edges or domain walls in thin-film magnetically coupled superconducting
- ferromagnetic bilayers. The corresponding Cooper pair wave function can be
viewed as a hybridization of two order parameter (OP) modes propagating along
the boundaries and/or domain walls. Different momenta of hybridized OP modes
result in the formation of vortex chains outgoing from the crossing point of
these channels. Near this crossing point the wave functions of the modes merge
giving rise to the increase in the critical temperature for a localized
superconducting state. The origin of this critical temperature enhancement
caused by the wave function squeezing is illustrated for a limiting case of
approaching parallel boundaries and/or domain walls. Using both the variational
method and numerical simulations we have studied the critical temperature
dependence and OP structure vs the applied magnetic field and the angle between
the crossing channels.Comment: 12 pages, 13 figure
Localization of superconductivity in superconductor-electromagnet hybrids
We investigate the nucleation of superconductivity in a superconducting Al
strip under the influence of the magnetic field generated by a current-carrying
Nb wire, perpendicularly oriented and located underneath the strip. The
inhomogeneous magnetic field, induced by the Nb wire, produces a spatial
modulation of the critical temperature T_c, leading to a controllable
localization of the superconducting order parameter (OP) wave function. We
demonstrate that close to the phase boundary T_c(B_ext) the localized OP
solution can be displaced reversibly by either applying an external
perpendicular magnetic field B_ext or by changing the amplitude of the
inhomogeneous field.Comment: 10 pages, 6 figure
Mesoscopic cross-film cryotrons: Vortex trapping and dc-Josephson-like oscillations of the critical current
We investigate theoretically and experimentally the transport properties of a
plain Al superconducting strip in the presence of a single straight
current-carrying wire, oriented perpendicular to the superconducting strip. It
is well known that the critical current of the superconducting strip, Ic, in
such cryotron--like system can be tuned by changing the current in the control
wire, Iw. We demonstrated that the discrete change in the number of the pinned
vortices/antivortices inside the narrow and long strip nearby the
current-carrying wire results in a peculiar oscillatory dependence of Ic on Iw.Comment: 8 pages, 8 figure
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