The Resonating Valence Bond State in La 2 CuO 4 and Superconductivity
1987; American Association for the Advancement of Science; Volume: 235; Issue: 4793 Linguagem: Inglês
10.1126/science.235.4793.1196
ISSN1095-9203
Autores Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoThe oxide superconductors, particularly those recently discovered that are based on La(2)CuO(4), 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.
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