Phase diagram of superconductors from nonperturbative flow equations.
Phase diagram of superconductors from nonperturbative flow equations.
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来自非微扰流动方程的超导体相图。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
C. Wetterich
中科院分区：
文献类型：
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作者：
Bastian Bergerhoff;F. Freire;D. Litim;S. Lola;C. Wetterich
用标量量子电动力学的三维场理论描述了超导体在相变附近的普遍行为。我们借助非摄动流动方程对模型进行了近似求解。根据标量耦合对规范耦合的相对强度，发现了一阶或二阶相变。二阶相变的区域由流动方程的一个不动点和相关的临界指数控制。我们还给出了三临界行为的近似描述，并简要讨论了与临界温度附近标度开始相关的交叉。对强第二类超导体的二级转变的最终确认需要进一步的分析，并对流动方程进行扩展截断。{版权所有}{1996年美国物理学会。}
The universal behavior of superconductors near the phase transition is described by the three-dimensional field theory of scalar quantum electrodynamics. We approximately solve the model with the help of nonperturbative flow equations. A first- or second-order phase transition is found depending on the relative strength of the scalar versus the gauge coupling. The region of a second-order phase transition is governed by a fixed point of the flow equations with associated critical exponents. We also give an approximate description of the tricritical behavior and briefly discuss the crossover relevant for the onset of scaling near the critical temperature. Final confirmation of a second-order transition for strong type-II superconductors requires further analysis with extended truncations of the flow equations. {copyright} {ital 1996 The American Physical Society.}