An interesting and novel effect has been observed in the form of a high resistance state below the superconducting transition temperature of Al nanorings. The resistance exceeded fifteen times the value of the normal state resistance even though the ring was superconducting. This counterintuitive effect can be explained in terms of charge imbalance caused by the nonequilibrium accumulation of quasiparticles near tilted normal-superconductor interfaces that occur naturally in highly constricted

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... anostructures. Simulations using finite element analysis have been performed which support the experimental results. Similar results have been observed in wires and disks, but the results of this work clarify and extend this previous work.