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.
@article{arxiv.cond-mat/0101402,
title = {Direct Transition Between a Singlet Mott Insulator and a Superconductor},
author = {M. Capone and M. Fabrizio and E. Tosatti},
journal= {arXiv preprint arXiv:cond-mat/0101402},
year = {2007}
}
Comments
4 pages, 3 figure, Changes to the figures. Accepted for publication on Physical Review Letters