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Superconducting correlations in ultra-small metallic grains

Guang-Shan Tian·Lei-Han Tang·Qing-Hu Chen
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Abstract

To describe the crossover from the bulk BCS superconductivity to a fluctuation-dominated regime in ultrasmall metallic grains, new order parameters and correlation functions, such as ``parity gap'' and ``pair-mixing correlation function'', have been recently introduced. In this paper, we discuss the small-grain behaviour of the Penrose-Onsager-Yang off-diagonal long-range order (ODLRO) parameter in a pseudo-spin representation. Relations between the ODLRO parameter and those mentioned above are established through analytical and numerical calculations.

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Guang-Shan Tian, Lei-Han Tang, Qing-Hu Chen. 2000-03-08. Superconducting correlations in ultra-small metallic grains. https://doi.org/10.1209/epl%2Fi2000-00279-7

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