1e and 2e superconductivity in spin liquids and spin crystals
Abstract
The recent, unexpected discoveries of superconductors with reported transition temperatures as high as 123 K have renewed the search for mechanisms with higher transition temperatures. Among the resulting proposals is one by Anderson in which an odd-electron insulator in a resonating valence-bond or quantum-spin-liquid state becomes superconducting via pair condensation when sufficiently doped. However, Kivelson, Rokhsar, and Sethra have suggested that doping such a state introduces singly charged boson defects which form a superconducting state via Bose-Einstein condensation. We resolve this apparent contradiction by pointing out the possible existence of a remarkable transition between superconductivity with an elementary charge of the supercurrent of e to superconductivity with an elementary charge of 2e with increased doping. Moreover, both kinds of superconductivity occur, even in the spin-crystal or Néel state.
- Publication:
-
Physical Review B
- Pub Date:
- June 1987
- DOI:
- 10.1103/PhysRevB.35.8720
- Bibcode:
- 1987PhRvB..35.8720C
- Keywords:
-
- Crystal Structure;
- Electron Spin;
- Liquid Phases;
- Mixed Oxides;
- Superconductivity;
- Transition Temperature;
- Barium Oxides;
- Copper Oxides;
- Neel Temperature;
- Strontium Compounds;
- Solid-State Physics;
- 74.70.Ya