Fully gapped superconductivity with no sign change in the prototypical heavy-fermion CeCu 2 Si 2

Abstract
Heavy electrons with extremely strong Coulomb repulsions can condense into a fully gapped s-wave superconducting state.
Funding Information
  • Japan Society for the Promotion of Science (ID0ETJBM18408, 25220710)
  • Japan Society for the Promotion of Science (ID0EERBM18409, 15H02106)
  • Japan Society for the Promotion of Science (ID0EG1BM18410, 15H05852)
  • UK Engineering and Physical Sciences Research Council (ID0EVBCM18411, EP/K016709/1)
  • UK Engineering and Physical Sciences Research Council (ID0E5GCM18412, EP/L015544/1)
  • Japan Society for the Promotion of Science (ID0EHMCM18413, 15H05883)