Phase separation models for cuprate stripe arrays

Abstract

An electronic phase separation model provides a natural explanation for a large variety of experimental results in the cuprates, including evidence for both stripes and larger domains, and a termination of the phase separation in the slightly overdoped regime, when the average hole density equals that on the charged stripes. Several models are presented for charged stripes, showing how density waves, superconductivity, and strong correlations compete with quantum size effects (QSEs) in narrow stripes. The energy bands associated with the charged stripes develop in the middle of the Mott gap, and the splitting of these bands can be understood by considering the QSE on a single ladder.

Mottness collapse and T -linear resistivity in cuprate superconductors

“…For example, Tokura and colleagues (Tokura et al, 1988) and Tutsch, et al(Tutsch et al, 1999) find optimal doping values of x = 0.21 and x = 0.24, respectively for YBCO. Others (Merz et al, 1998a;Drechsler et al, 1997;Markiewicz & Kusko, 2002) have reached similar conclusions. Hardy and collaborators (Liang et al, 2006) have investigated the validity of Eq.…”

Fermi surface evolution and collapse of the Mott pseudogap inNd2−xCexKusko1, Markiewicz2, Lindroos3 et al. 2002Phys. Rev. BSelf Cite

“…9 Another aspect which bears emphasis is that for hole doping the AFM solution obtained in the MF is unstable towards the formation of incommensurate phases or phase separation. 10,11 In sharp contrast, we find that in the electrondoped case the MF and SCR solutions do not show such an instability. These results indicate that the MF solutionwhen interpreted properly along the lines of the preceding paragraph-can be remarkably valuable in describing the electron-doped cuprates.…”

“…In the one-band Hubbard model 29 holes first enter the LHB as small hole pockets around (/2,/2). However, as already noted, 10 the uniformly doped AFM state is unstable and leads to complications of ͑nanoscale͒ phase separation and stripe physics not expected for electron doping 11 . Indeed, characteristic experimental signatures of stripe order, e.g., the 1/8 anomaly and the NQR wipeout, appear greatly attenuated if not absent in NCCO, 30 and E F shifts smoothly with doping into the UHB.…”

Competing order scenario of two-gap behavior in hole-doped cuprates

“…5, suggesting that in a multi-domain sample it might be hard to distinguish this behavior from the experimental two-gap data. Finally, we have studied a linear antiferromagnetic (LAFM) phase 41 , which has a one-dimensional ordering vector (π, 0), as might be seen in a stripe phase. However, we find that the resulting two gap structure displays a very different symmetry pattern, which is not consistent with experiments.…”