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Theory of Upper Critical Field without Energy Quantization

L. Wang·H. S. Lim·C. K. Ong
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Abstract

Conventional theories for determining upper critical fields are inevitably related to the lowest eigenvalues of appropriate equations. In this Letter, a new theory of upper critical fields is designed and justified. Using MgB$_2$ as modeling prototype, our computations are in excellent agreement with the Ginzburg-Landau theory. The long-standing issue, the upward curvature of the upper critical field, is found to be a manifestation of the crossover of the order parameter. The current theory is an alternative to the traditional technique of energy quantization in determining upper critical fields.

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L. Wang, H. S. Lim, C. K. Ong. 2004-04-02. Theory of Upper Critical Field without Energy Quantization. https://arxiv.org/abs/cond-mat/0404043

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