Upper critical field in two-band superconductivity
Upper critical field in two-band superconductivity
复制标题
双带超导的上临界场
DOI：
10.1103/physrevb.72.024538
复制
发表时间：
2005
影响因子：
3.7
通讯作者：
J. P. Carbotte
中科院分区：
文献类型：
--
作者：
M. Mansor;J. P. Carbotte
我们使用 Werthamer-Helfand-Hohenberg 方程对强耦合和双带超导的推广来研究上临界场 ${H}_{c2}(T)$ 对电子声子耦合和费米速度各向异性以及带内和带间杂质散射的任意值的依赖性。对于$\mathrm{Mg}{\mathrm{B}}_{2}$这样的层状系统，临界磁场$(H)$本身的温度依赖性以及$ab$（$H$在基面内）和$c$（$H$垂直于基面）方向之间的各向异性比${H}_{c2}^{ab}(T)∕{H}_{c2}^{c}(T)$被研究。对于 $\mathrm{Mg}{\mathrm{B}}_{2}$，发现各向异性比对 $\ensuremath{\pi}$ 频带中的带内杂质散射特别敏感。
We use a generalization of the Werthamer-Helfand-Hohenberg equations to strong coupling and to two-band superconductivity to study the dependence of the upper critical field ${H}_{c2}(T)$ on anisotropy in the electron-phonon coupling and in the Fermi velocities, as well as on arbitrary values of intraband and interband impurity scattering. For a layered system such as $\mathrm{Mg}{\mathrm{B}}_{2}$, the temperature dependence of the critical magnetic $(H)$ field itself and the anisotropy ratio ${H}_{c2}^{ab}(T)∕{H}_{c2}^{c}(T)$ between $ab$ ($H$ in the basal plane) and $c$ ($H$ perpendicular to the basal plane) directions are studied. For $\mathrm{Mg}{\mathrm{B}}_{2}$, the anisotropy ratio is found to be particularly sensitive to intraband impurity scattering in the $\ensuremath{\pi}$ band.