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One-Band Tight-Binding Model Parametrization Of The High-Tc Cuprates Including The Effect Of Kz Dispersion, R. Markiewicz, S. Sahrakorpi, M. Lindroos, Hsin Lin, A. Bansil
One-Band Tight-Binding Model Parametrization Of The High-Tc Cuprates Including The Effect Of Kz Dispersion, R. Markiewicz, S. Sahrakorpi, M. Lindroos, Hsin Lin, A. Bansil
Arun Bansil
We discuss the effects of interlayer hopping and the resulting kz dispersion in the cuprates within the framework of the one-band tight-binding model Hamiltonian. Specific forms of the dispersion relations in terms of the in-plane hopping parameters t, t′, t″, and t‴ and the effective interlayer hopping tz in La₂₋ₓSrₓCuO₄ (LSCO) and Nd₂₋ₓCeₓCuO₄ (NCCO) and the added intracell hopping tbi between the CuO₂ bilayers in Bi₂Sr₂CaCu₂O₈ (Bi2212) are presented. The values of the “bare” parameters are obtained via fits with the first-principles local-density-approximation- (LDA-) based band structures in LSCO, NCCO, and Bi2212. The corresponding “dressed” parameter sets which account for …
Dielectric Signatures Of Lattice Instabilities At 32k And 245k In $La_{2-Y}Sr_{Y}Mo_{4+X}$ (M=Cu,Ni) Cuprates And Nickelates, P. Parimi, N. Hakim, F. Chou, S. Cheong, S. Sridhar
Dielectric Signatures Of Lattice Instabilities At 32k And 245k In $La_{2-Y}Sr_{Y}Mo_{4+X}$ (M=Cu,Ni) Cuprates And Nickelates, P. Parimi, N. Hakim, F. Chou, S. Cheong, S. Sridhar
Srinivas Sridhar
New dielectric transitions are observed at common temperatures 32K and 245K, in isostructural $La_{2}CuO_{4+x}$ and $La_{5/3}Sr_{1/3}NiO_{4},$ that are signatures of local lattice (octahedral) instabilities. The present dielectric transitions reveal new aspects of the phase diagram of the perovskite cuprates and nickelates. They suggest that competition and coexistence of superconductivity with dielectricity occurs that is analogous to that between superconductivity and anti-ferromagnetism. These results also indicate that inhomogeneous electronic states, such as charge stripes and oxygen ordering, are strongly connected to underlying lattice instabilities.