Two-band superconductivity in doped SrTiO3 films and interfaces
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 1, 014510- p.Article in journal (Refereed) Published
We investigate the possibility of multiband superconductivity in SrTiO3 films and interfaces using a two-dimensional two-band model. In the undoped compound, one of the bands is occupied whereas the other is empty. As the chemical potential shifts due to doping by negative charge carriers or application of an electric field, the second band becomes occupied and gives rise to a strong enhancement of the transition temperature and a sharp feature in the gap functions, which is manifested in the local density of states spectrum. By comparing our results with tunneling experiments in Nb-doped SrTiO3, we find that intraband pairing dominates over interband pairing, unlike other known multiband superconductors. Given the similarities with the value of the transition temperature and with the band structure of LaAlO3/SrTiO3 heterostructures, we speculate that the superconductivity observed in SrTiO3 interfaces may be similar in nature to that of bulk SrTiO3, involving multiple bands with distinct electronic occupations.
Place, publisher, year, edition, pages
2013. Vol. 87, no 1, 014510- p.
High-Temperature Superconductivity, Laalo3/Srtio3 Interface, Oxides, Density, Physics, Bands
IdentifiersURN: urn:nbn:se:kth:diva-119051DOI: 10.1103/PhysRevB.87.014510ISI: 000313939200009ScopusID: 2-s2.0-84872849952OAI: oai:DiVA.org:kth-119051DiVA: diva2:609906
QC 201303052013-03-082013-03-052013-08-27Bibliographically approved