Effect of spin-orbit coupling on the electron-phonon interaction of the superconductors Pb and Tl
Effect of spin-orbit coupling on the electron-phonon interaction of the superconductors Pb and Tl
复制标题
DOI：
10.1103/physrevb.81.174527
复制
发表时间：
2010-05-01
影响因子：
3.7
通讯作者：
Chulkov, E. V.
中科院分区：
文献类型：
--
作者：
Heid, R.;Bohnen, K. -P.;Chulkov, E. V.
利用密度泛函理论研究了自旋轨道耦合对Pb和Tl的电子-声子相互作用和配对强度的影响。对于Pb，我们发现SOC使耦合常数lambda增加了44%，解决了长期存在的难题，即在以前的第一性原理计算中始终获得过小的lambda值。soc诱导λ增强的根源在于声子谱的软化和电子-声子耦合矩阵元素的增加。相比之下，对于相邻元素Tl， SOC对声子谱和电子-声子相互作用的影响较弱，导致lambda总体降低了12%。在这两种情况下，SOC的加入提高了与实验的一致性。
The influence of spin-orbit coupling (SOC) on the electron-phonon interaction and on the pairing strength is investigated for Pb and Tl within density-functional theory. For Pb we find that SOC increases the coupling constant lambda by 44%, solving the longstanding puzzle of too small lambda values obtained consistently in previous first-principles calculations. The origin of the SOC-induced enhancement of lambda lies both in a softening of the phonon spectrum and in an increase in the electron-phonon coupling matrix elements. In contrast, for the neighboring element Tl only weak effects of SOC on the phonon spectrum and the electron-phonon interaction is obtained, leading to an overall reduction in lambda by 12%. In both cases, the inclusion of SOC improves the agreement with experiment.