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تسجيل مستخدم جديدOverscreening Diamagnetism in Cylindrical Superconductor-Normal Metal-Heterostructures
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We study the linear diamagnetic response of a superconducting cylinder coated by a normal-metal layer due to the proximity effect using the clean limit quasiclassical Eilenberger equations. We compare the results for the susceptibility with those for a planar geometry. Interestingly, for $Rsim d$ the cylinder exhibits a stronger overscreening of the magnetic field, i.e., at the interface to the superconductor it can be less than (-1/2) of the applied field. Even for $Rgg d$, the diamagnetism can be increased as compared to the planar case, viz. the magnetic susceptibility $4pichi$ becomes smaller than -3/4. This behaviour can be explained by an intriguing spatial oscillation of the magnetic field in the normal layer.
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