Charge Imbalance Effects on Interlayer Hopping and Fermi Surfaces in Multilayered High-T_c Cuprates

TL;DR

This paper investigates how charge imbalance affects interlayer hopping and Fermi surface splitting in multilayered high-T_c cuprates, revealing doping-dependent interlayer coupling and predicting observable Fermi surface features.

Contribution

It introduces a doping-dependent effective interlayer hopping model considering charge imbalance, and calculates Fermi surface splitting in multilayered cuprates using mean-field theory.

Findings

Effective interlayer hopping scales with the square root of doping in adjacent planes.

Distinct interlayer hopping values for inner and outer planes due to charge imbalance.

Predicted Fermi surface splitting observable via ARPES measurements.

Abstract

We study doping dependence of interlayer hoppings, t_\perp, in multilayered cuprates with four or more CuO_2 planes in a unit cell. When the double occupancy is forbidden in the plane, an effective amplitude of t_\perp in the Gutzwiller approximation is shown to be proportional to the square root of the product of doping rates in adjacent two planes, i.e., t^eff_\perp \propto t_\perp \sqrt{\delta_1\delta_2}, where \delta_1 and \delta_2 represent the doping rates of the two planes. More than three-layered cuprates have two kinds of \cuo planes, i.e., inner- and outer planes (IP and OP), resulting in two different values of t^eff_{\perp}, i.e., t^eff_\perp 1 \propto t_\perp \sqrt{\delta_IP \delta_IP} between IP's, and t^eff_\perp 2 \propto t_\perp \sqrt{\delta_IP \delta_OP} between IP and OP. Fermi surfaces are calculated in the four-layered t-t'-t''-J model by the mean-field theory. The order parameters, the renormalization factor of t_\perp, and the site-potential making the charge imbalance between IP and OP are self-consistently determined for several doping rates. We show the interlayer splitting of the Fermi surfaces, which may be observed in the angle resolved photoemission spectroscopy measurement.