Low Temperature Physics: 37, 261 (2011); https://doi.org/10.1063/1.3580606 (7 pages)
Fizika Nizkikh Temperatur: Volume 37, Number 3 (March 2011), p. 334-343    ( to contents , go back )

Electronic structure of hole centers in CuO2 planes of cuprates

A.S. Moskvin and Yu.D. Panov

Ural State University, Ekaterinburg 620083, Russia
E-mail: Alexandr.Moskvin@usu.ru
pos Анотація:

Received September 24,2010

Abstract

Both theoretical considerations and numerous experimental data point to a more complicated nature of the valence hole states in doped cuprates than it is predicted by the simple Zhang–Rice model. Actually we deal with the competition of conventional hybrid Cu 3d–O 2p b1g µ dx2 - y2 -state and purely oxygen nonbonding state with a2g- and eux, y µ px, y -symmetry. Accordingly, the ground state of such a non Zhang–Rice hole center CuO45− as a cluster analog of Cu3+ ion should be described by a complex 1A1g1,3B2g1,3Eu multiplet with several competing charge, orbital, and spin order parameters, like conventional ones (e.g., spin moment or Ising-like orbital magnetic moment) and unconventional, or hidden ones (e.g., intra-plaquette's staggered order of Ising-like oxygen orbital magnetic moment or combined spin-quadrupole ordering). The non Zhang–Rice hole CuO45− centers should be considered as singlet-triplet pseudo-Jahn-Teller centers prone to strong vibronic coupling. The complex non Zhang–Rice structure of the ground state multiplet of hole centers manifests itself in many unconventional properties of doped cuprates, in particular, in a pseudo-gap regime.

PACS: 74.25.–q Properties of superconductors;
PACS: 74.72.–h Cuprate superconductors;
PACS: 74.72.Kf Pseudogap regime.

Key words: doped cuprates, Zhang-Rice singlet, hole centers, pseudo-gap regime.

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