The role of spin-orbit coupling in the electronic structure of iron-based superconductors (Phys. Status Solidi B 1/2017)

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• 作者：Sergey Borisenko ; Daniil Evtushinsky ; Zhonghao Liu ; Igor Morozov ; Rhea Kappenberger ; Sabine Wurmehl ; Bernd Bü ; chner ; Alexander Yaresko ; Timur Kim ; Moritz Hoesch ; Thomas Wolf and Nikolai Zhigadlo
• 刊名：physica status solidi (b)
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：254
• 期：1
• 全文大小：717K
• ISSN：1521-3951

文摘

The fine details of the electronic structure of iron-based superconductors are responsible for the complete loss of resistance at relatively high temperatures. Although the underlying mechanism of this phenomenon is not yet fully understood, the high-resolution measurements of the lowenergy electronic states may help to find the answer. The results of such experiments for LiFeAs obtained by angleresolved photoemission spectroscopy (ARPES) reveal the presence of spin-orbit splitting, a fundamental interaction which is suggested to contribute to the pairing of electrons (see the Feature Article by Borisenko et al., article no. 1600550). The Fermi surface map (upper row of the cover pictures, third panel) shows that spin-orbit coupling lifts the degeneracy in those positions where the electron-like pockets crossed in the non-relativistic case. This interaction converts the Fermi surfaces encircling the corner of the Brillouin zone to clearly separated inner and outer electron pockets. The observation that those electronic states which are split–most (centers of the middle and lower row panels) support the largest superconducting gap argues for a relationship between spin-orbit coupling and Cooper pairing in iron-based materials. [Adopted from Nature Phys. 12, 311 (2016).]