The origin of multiple superconducting gaps in MgB2

S. Souma, Y. Machida, T. Sato, T. Takahashi (), H. Matsui, S.-C. Wang, H. Ding, A. Kaminski, J. C. Campuzano, S. Sasaki and K. Kadowaki
Additional contact information
S. Souma: Tohoku University
Y. Machida: Tokyo Institute of Technology
T. Sato: Tohoku University
T. Takahashi: Tohoku University
H. Matsui: Tohoku University
S.-C. Wang: Boston College
H. Ding: Boston College
A. Kaminski: Argonne National Laboratory
J. C. Campuzano: Argonne National Laboratory
S. Sasaki: Tokyo Institute of Technology
K. Kadowaki: University of Tsukuba

Nature, 2003, vol. 423, issue 6935, 65-67

Abstract: Abstract Magnesium diboride, MgB2, has the highest transition temperature (Tc = 39 K) of the known metallic superconductors1. Whether the anomalously high Tc can be described within the conventional BCS (Bardeen–Cooper–Schrieffer) framework2 has been debated. The key to understanding superconductivity lies with the ‘superconducting energy gap’ associated with the formation of the superconducting pairs. Recently, the existence of two kinds of superconducting gaps in MgB2 has been suggested by several experiments3,4,5,6,7,8,9; this is in contrast to both conventional and high-Tc superconductors. A clear demonstration of two gaps has not yet been made because the previous experiments lacked the ability to resolve the momentum of the superconducting electrons. Here we report direct experimental evidence for the two-band superconductivity in MgB2, by separately observing the superconducting gaps of the σ and π bands (as well as a surface band). The gaps have distinctly different sizes, which unambiguously establishes MgB2 as a two-gap superconductor10,11.

Date: 2003
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/nature01619 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:423:y:2003:i:6935:d:10.1038_nature01619

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature01619

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().