Phase transition into the superconducting mixed state and the de Haas-van Alphen effect
Phase transition into the superconducting mixed state and the de Haas-van Alphen effect
复制标题
进入超导混合态的相变和德哈斯-范阿尔芬效应
DOI：
10.1080/014186300255465
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
V. Mineev
中科院分区：
文献类型：
--
作者：
V. Mineev
导出了Abrikosov晶格上超导混合态在上临界场附近的自由能以序参数的平均苏拉尔模幂的Landau展开式。在Gor‘kov形式的框架下，对超越准经典近似极限的三维各向同性BCS模型进行了解析计算，即考虑了奥粒子能级的朗道量子化。对于有限但足够高的晶体纯度，在较低的温度下进行推导。考虑了泡利顺磁项的影响。发现了混合态的临界温度、有序参数的幅值和磁化强度(德哈斯-范阿尔芬效应)的量子振荡。建立了临界涨落平均场方法(Ginzburg准则)对所考虑的相变的有效性限制。
Abstract The Landau expansion for the free energy of the superconducting mixed state near the upper critical field in powers of the sauare modulus of the order parameter averaged over an Abrikosov lattice is derived. The analytical calculations have been carried out in the framework of the Gor'kov formalism for a 3-dimensional isotropic BCS model beyond the limits of the quasiclassical approximation, that is, with Landau auantization of the auasiparticle energy levels taken into consideration. The derivation is performed at Iow temperature for finite but high enough crystal purity. The effect of Pauli paramagnetic terms is taken into account. The quantum oscillations of the critical temperature, the order parameter's amplitude and the magnetization (de Haas-van Alphen effect) in the mixed state are found. The limitation for the validity of a mean field approach due to critical fluctuations (Ginzburg criterion) for the phase transition under consideration is established.