We argue that a normal Fermi liquid and a singlet, spin-gapped Mott insulator cannot be continuously connected, and that some intermediate phase must intrude between them. By explicitly working out a case study where the singlet insulator is stabilized by orbital degeneracy and an inverted Hund's rule coupling, mimicking a Jahn-Teller effect, we find that the intermediate phase is a superconductor.
Physical Review Letters
- Pub Date:
- June 2001
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity
- 4 pages, 3 figure, Changes to the figures. Accepted for publication on Physical Review Letters