Weber blockade theory of magnetoresistance oscillations in superconducting strips

TL;DR

This paper introduces the Weber blockade theory, explaining magnetoresistance oscillations in superconducting strips through vortex dynamics and duality with quantum dots, revealing conductance patterns akin to Coulomb blockade.

Contribution

It proposes a novel vortex-based model using vortex/charge duality to interpret magnetoresistance oscillations as Weber blockade diamonds in superconducting strips.

Findings

Identification of vortex motion as the key dissipation mechanism.

Prediction of Weber blockade diamonds in conductance maps.

Correlation of conductance maxima with equal-energy vortex states.

Abstract

Recent experiments on the conductance of thin, narrow superconducting strips have found periodic fluctuations, as a function of the perpendicular magnetic field, with a period corresponding to approximately two flux quanta per strip area [A. Johansson et al., Phys. Rev. Lett. {\bf 95}, 116805 (2005)]. We argue that the low-energy degrees of freedom responsible for dissipation correspond to vortex motion. Using vortex/charge duality, we show that the superconducting strip behaves as the dual of a quantum dot, with the vortices, magnetic field, and bias current respectively playing the roles of the electrons, gate voltage and source-drain voltage. In the bias-current vs. magnetic-field plane, the strip conductance displays what we term `Weber blockade' diamonds, with vortex conductance maxima (i.e., electrical resistance maxima) that, at small bias-currents, correspond to the fields at which strip states of $N$ and $N+1$ vortices have equal energy.