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Parity-Affected Superconductivity in Ultrasmall Metallic Grains

Jan von Delft·Dmitrii S. Golubev·Wolfgang Tichy·Andrei D. Zaikin
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Abstract

We investigate the breakdown of BCS superconductivity in {\em ultra}\/small metallic grains as a function of particle size (characterized by the mean spacing $d$ between discrete electronic eigenstates), and the parity ($P$ = even/odd) of the number of electrons on the island. Assuming equally spaced levels, we solve the parity-dependent BCS gap equation for the order parameter $Δ_P (d,T)$. Both the $T=0$ critical level spacing $d_{c,P} $ and the critical temperature $T_{c,P} (d)$ at which $Δ_P = 0$ are parity dependent, and both are so much smaller in the odd than the even case that these differences should be measurable in current experiments.

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Jan von Delft, Dmitrii S. Golubev, Wolfgang Tichy, Andrei D. Zaikin. 1996-04-11. Parity-Affected Superconductivity in Ultrasmall Metallic Grains. https://doi.org/10.1103/physrevlett.77.3189

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