Temperature dependence of the spin susceptibility of layered cuprates in the pseudogap phase: Comparison with the knight shift data for the Cu(2) site in YBa_2Cu_4O_8 and Bi_2Sr _2CaCu_2O_(8 + x)

摘要

The temperature dependences of the Knight shift at the Cu(2) site in YBa_2Cu_4O_8 and Bi_2Sr _2CaCu_2O_(8 + x) compounds were analyzed based on the band structure parameter extracted from photoemission data. Different scenarios for the pseudogap state are discussed, and the densities of states of quasiparticle excitations are calculated.