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Title: Momentum dependence of the superconducting gap and in-gap states in MgB 2 multiband superconductor

Abstract

We use tunable laser-based angle-resolved photoemission spectroscopy to study the electronic structure of the multiband superconductor MgB2. These results form the baseline for detailed studies of superconductivity in multiband systems. We find that the magnitude of the superconducting gap on both σ bands follows a BCS-like variation with temperature with Δ0 ~ 7meV. Furthermore, the value of the gap is isotropic within experimental uncertainty and in agreement with a pure s-wave pairing symmetry. We observe in-gap states confined to kF of the σ band that occur at some locations of the sample surface. As a result, the energy of this excitation, ~ 3 meV, was found to be somewhat larger than the previously reported gap on π Fermi sheet and therefore we cannot exclude the possibility of interband scattering as its origin.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1]
  1. Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1227380
Alternate Identifier(s):
OSTI ID: 1198619
Report Number(s):
IS-J-8675
Journal ID: ISSN 1098-0121; PRBMDO
Grant/Contract Number:  
AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 91; Journal Issue: 21; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Mou, Daixiang, Jiang, Rui, Taufour, Valentin, Bud'ko, S. L., Canfield, P. C., and Kaminski, Adam. Momentum dependence of the superconducting gap and in-gap states in MgB2 multiband superconductor. United States: N. p., 2015. Web. doi:10.1103/PhysRevB.91.214519.
Mou, Daixiang, Jiang, Rui, Taufour, Valentin, Bud'ko, S. L., Canfield, P. C., & Kaminski, Adam. Momentum dependence of the superconducting gap and in-gap states in MgB2 multiband superconductor. United States. https://doi.org/10.1103/PhysRevB.91.214519
Mou, Daixiang, Jiang, Rui, Taufour, Valentin, Bud'ko, S. L., Canfield, P. C., and Kaminski, Adam. 2015. "Momentum dependence of the superconducting gap and in-gap states in MgB2 multiband superconductor". United States. https://doi.org/10.1103/PhysRevB.91.214519. https://www.osti.gov/servlets/purl/1227380.
@article{osti_1227380,
title = {Momentum dependence of the superconducting gap and in-gap states in MgB2 multiband superconductor},
author = {Mou, Daixiang and Jiang, Rui and Taufour, Valentin and Bud'ko, S. L. and Canfield, P. C. and Kaminski, Adam},
abstractNote = {We use tunable laser-based angle-resolved photoemission spectroscopy to study the electronic structure of the multiband superconductor MgB2. These results form the baseline for detailed studies of superconductivity in multiband systems. We find that the magnitude of the superconducting gap on both σ bands follows a BCS-like variation with temperature with Δ0 ~ 7meV. Furthermore, the value of the gap is isotropic within experimental uncertainty and in agreement with a pure s-wave pairing symmetry. We observe in-gap states confined to kF of the σ band that occur at some locations of the sample surface. As a result, the energy of this excitation, ~ 3 meV, was found to be somewhat larger than the previously reported gap on π Fermi sheet and therefore we cannot exclude the possibility of interband scattering as its origin.},
doi = {10.1103/PhysRevB.91.214519},
url = {https://www.osti.gov/biblio/1227380}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 21,
volume = 91,
place = {United States},
year = {Mon Jun 29 00:00:00 EDT 2015},
month = {Mon Jun 29 00:00:00 EDT 2015}
}

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Cited by: 20 works
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Works referenced in this record:

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Works referencing / citing this record:

Self-Consistent Two-Gap Description of MgB2 Superconductor
journal, August 2019


Two-gap and three-gap superconductivity in AlB 2 -based films
journal, September 2019


Observation of topological surface states in the high-temperature superconductor MgB2
text, January 2019