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arXiv 1902.09018cond-mat.supr-con
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I型和II型之间的各向异性超导体

Anisotropic Superconductors Between Types I and II

T. T. Saraiva, A. Vagov, V. M. Axt, J. Albino Aguiar, A. A. Shanenko

摘要:

自对偶性或磁特征长度与凝聚特征长度之间的匹配是各向同性超导体在临界Bogomolnyi点(B点)的基本性质。凝聚体的自对偶态是无限简并的,这是在临界温度T_c附近超导类型之间急剧转变的核心原因。在T_c以下,凝聚体中的非定域相互作用消除了简并性,导致出现介于I型和II型之间的有限型间(IT)域。该畴呈现出具有奇异场凝聚配置和非标准磁响应的混合态,这在传统超导类型的二分法中无法理解。乍一看,这幅图并不适用于各向异性系统,因为对于方向相关的特征长度,通常不能期望凝聚体和磁场之间的空间匹配。然而,与这些期望相反,在这里,我们证明了各向异性超导体遵循相同的情况下,I型和II型之间的互换。在各向异性材料中,IT域由有效各向同性模型的B点控制,该模型通过初始各向异性形式主义的适当缩放变换获得。这种转变取决于所施加的磁场的方向,因此强各向异性材料的超导类型可以取决于该方向。

英文摘要:

Self-duality or matching between the magnetic and condensate characteristic lengths is a fundamental property of isotropic superconductors at the critical Bogomolnyi point (B-point). The self-dual state of the condensate is infinitely degenerate, which is the core reason for the sharp transition between the superconductivity types in the nearest vicinity of the critical temperature T_c. Below T_c non-local interactions in the condensate remove the degeneracy, which leads to the appearance of a finite intertype (IT) domain between types I and II. This domain exhibits the mixed state with exotic field-condensate configurations and non-standard magnetic response, which cannot be understood within the dichotomy of the conventional superconductivity types. At a first glance, this picture does not apply to an anisotropic system because no spatial matching between the condensate and magnetic field can be generally expected for direction-dependent characteristic lengths. However, contrary to these expectations, here we demonstrate that anisotropic superconductors follow the same scenario of the interchange between types I and II. In anisotropic materials the IT domain is governed by the B-point of the effective isotropic model obtained by the appropriate scaling transformation of the initial anisotropic formalism. This transformation depends on the direction of the applied magnetic field, and thus the superconductivity type of strongly anisotropic materials can be dependent on this direction.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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