https://doi.org/10.1140/epjb/e2016-60849-4
Regular Article
Pseudogaps in the three-band Hubbard model
Institute of Physics, University of Tartu,
Ravila 14c,
50411
Tartu,
Estonia
a e-mail: alekseis@ut.ee
Received:
27
October
2015
Received in final form:
12
December
2015
Published online:
6
April
2016
Using the strong coupling diagram technique, the energy spectrum of the three-band Hubbard model is investigated. In these calculations, the series in powers of the copper-oxygen hybridization for the irreducible part is approximated by two lowest-order terms. For parameters of hole-doped cuprates the calculated energy spectrum consists of lower and upper Hubbard subbands of predominantly copper nature, oxygen bands with some admixture of copper states and the Zhang-Rice states of mixed nature. The spectrum contains two pseudogaps, the lower of which separates the Hubbard subband from Zhang-Rice and oxygen bands. The pseudogaps arise due to multiple reabsorption of carriers in states with double occupancy of sites by holes or electrons.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2016