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The Average Kinetic Energy of the Superconducting State

Mauro M. Doria·S. Salem-Sugui Jr.·I. G. de Oliveira·L. Ghivelder·E. H. Brandt
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Abstract

Isothermal magnetization curves are plotted as the magnetization times the magnetic induction, $4 πM \cdot B$, versus the applied field, H. We show here that this new curve is the average kinetic energy of the superconducting state versus the applied field, for type-II superconductors with a high Ginzburg-Landau parameter $κ$. The maximum of $4 πM \cdot B$ occurs at a field, $H^{*}$, directly related to the upper critical field, $H_{c2}$, suggesting that $H_{c2}(T)$ may be extracted from such plots even in cases when it is too high for direct measurement. We obtain these plots both theoretically, from the Ginzburg-Landau theory, and experimentally, using a Niobium sample with $T_c = 8.5 K$, and compare them.

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Mauro M. Doria, S. Salem-Sugui Jr., I. G. de Oliveira, L. Ghivelder, E. H. Brandt. 2002-01-08. The Average Kinetic Energy of the Superconducting State. https://doi.org/10.1103/physrevb.65.144509

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