• Rapid Communication

Cooper pairing in the insulating valence band in iron-based superconductors

Lun-Hui Hu, Wei-Qiang Chen, and Fu-Chun Zhang
Phys. Rev. B 91, 161108(R) – Published 23 April 2015

Abstract

Conventional Cooper pairing arises from attractive interaction of electrons in the metallic bands. A recent experiment on Co-doped LiFeAs shows superconductivity in the insulating valence band, which is evolved from a metallic hole band upon doping. Here we examine this phenomenon by studying superconductivity in a three-orbital Hamiltonian relevant to the doped LiFeAs. We show explicitly that Cooper pairing of the insulating hole band requires a finite pairing interaction strength. For strong coupling, the superconductivity in the hole band is robust against the sink of the hole band below the Fermi level. Our theory predicts a substantial upward shift of the chemical potential in the superconducting transition for Co-doped LiFeAs.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 12 March 2015
  • Revised 7 April 2015

DOI:https://doi.org/10.1103/PhysRevB.91.161108

©2015 American Physical Society

Authors & Affiliations

Lun-Hui Hu1,2, Wei-Qiang Chen3,*, and Fu-Chun Zhang1,2

  • 1Department of Physics, Zhejiang University, Hangzhou, China
  • 2Collaborative Innovation Center of Advanced Microstructures, Nanjing, China
  • 3Department of Physics, South University of Science and Technology of China, Shenzhen, China

  • *chenwq@sustc.edu.cn

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 91, Iss. 16 — 15 April 2015

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×