The resonating valence bond state in La2CuO4 and superconductivity
Abstract
The oxide superconductors, particularly those recently discovered that are based on La2CuO4, have a set of peculiarities that suggest a common, unique mechanism: they tend in every case to occur near a metal-insulator transition into an odd-electron insulator with peculiar magnetic properties. This insulating phase is proposed to be the long-sought 'resonating-valence-bond' state or 'quantum spin liquid' hypothesized in 1973. This insulating magnetic phase is favored by low spin, low dimensionality, and magnetic frustration. The preexisting magnetic singlet pairs of the insulating state become charged superconducting pairs when the insulator is doped sufficiently strongly. The mechanism for superconductivity is hence predominantly electronic and magnetic, although weak phonon interactions may favor the state. Many unusual properties are predicted, especially of the insulating state.
- Publication:
-
Science
- Pub Date:
- March 1987
- DOI:
- 10.1126/science.235.4793.1196
- Bibcode:
- 1987Sci...235.1196A
- Keywords:
-
- Chemical Bonds;
- Copper Compounds;
- Lanthanum Compounds;
- Superconductors;
- Valence;
- Crystal Lattices;
- Doped Crystals;
- Insulators;
- Particle Spin;
- Temperature Effects;
- Solid-State Physics