Work

Multi-band Superconductors have Enhanced Critical Temperatures

Year: 2026

Type: article

Abstract: We introduce a multi-band BCS free energy functional and prove that for a multi-band superconductor the effect of inter-band coupling can only increase the critical temperature, irrespective of its attractive or repulsive nature and its strength. Further, for weak coupling and weaker inter-band coupling, we prove that the dependence of the increase in critical temperature on the inter-band coupling is (1) linear, if there are two or more equally strongly superconducting bands, or (2) quadratic, if there is only one dominating band.

Source: Annales Henri Poincaré

DOI: 10.1007/s00023-026-01706-y

Authors: Joscha Henheik, Edwin Langmann, Asbjørn Bækgaard Lauritsen

Institutions: Institute of Science and Technology Austria, KTH Royal Institute of Technology

Language: English

Topic: Physics of Superconductivity and Magnetism

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,090