Momentum-dependent multiple gaps in magnesium diboride probed by electron tunnelling spectroscopy.
Nat Commun
; 3: 619, 2012 Jan 10.
Article
em En
| MEDLINE
| ID: mdl-22233629
ABSTRACT
The energy gap is the most fundamental property of a superconductor. MgB(2), a superconductor discovered in 2001, exhibits two different superconducting gaps caused by the different electron-phonon interactions in two weakly interacting bands. Theoretical calculations predict that the gap values should also vary across the Fermi surface sheets of MgB(2). However, until now, no such variation has been observed. It has been suggested that two gap values were sufficient to describe real MgB(2) samples. Here we present an electron tunnelling spectroscopy study on MgB(2)/native oxide/Pb tunnel junctions that clearly shows a distribution of gap values, confirming the importance of the anisotropic electron-phonon interaction. The gap values, and their spreads found from the tunnel junction measurements, provide valuable experimental tests for various theoretical approaches to the multi-band superconductivity in MgB(2).
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Física
/
Compostos de Boro
/
Compostos de Magnésio
/
Espectroscopia Fotoeletrônica
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article