Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe0.55Se0.45

H. Miao; P. Richard; Y. Tanaka; K. Nakayama; T. Qian; K. Umezawa; T. Sato; Y. -M. Xu; Y. -B. Shi; N. Xu; X. -P. Wang; P. Zhang; H. -B. Yang; Z. -J. Xu; J. S. Wen; G. -D. Gu; X. Dai; J. -P. Hu; T. Takahashi; H. Ding

doi:10.1103/physrevb.85.094506

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arXiv · 1107.0985

Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe0.55Se0.45

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Abstract

The momentum distribution of the energy gap opening at the Fermi level of superconductors is a direct fingerprint of the pairing mechanism. While the phase diagram of the iron-based superconductors promotes antiferromagnetic fluctuations as a natural candidate for electron pairing, the precise origin of the interaction is highly debated. We used angle-resolved photoemission spectroscopy to reveal directly the momentum distribution of the superconducting gap in FeTe1-xSex, which has the simplest structure of all iron-based superconductors. We found isotropic superconducting gaps on all Fermi surfaces whose sizes can be fitted by a single gap function derived from a strong coupling approach, strongly suggesting local antiferromagnetic exchange interactions as the pairing origin.

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H. Miao, P. Richard, Y. Tanaka, K. Nakayama, T. Qian, K. Umezawa, T. Sato, Y. -M. Xu, Y. -B. Shi, N. Xu, X. -P. Wang, P. Zhang, H. -B. Yang, Z. -J. Xu, J. S. Wen, G. -D. Gu, X. Dai, J. -P. Hu, T. Takahashi, H. Ding. 2011-07-05. Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe0.55Se0.45. https://doi.org/10.1103/physrevb.85.094506

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