Doping Evolution of Nodal Electron Dynamics in Trilayer Cuprate Superconductor Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10+\delta}$ Revealed by Laser-Based Angle-Resolved Photoemission Spectroscopy

TL;DR

This study investigates how the electron dynamics at the nodal points in a trilayer cuprate superconductor evolve with doping, revealing key features of the electronic structure and charge distribution that influence high-temperature superconductivity.

Contribution

It provides the first detailed doping-dependent analysis of nodal electron behavior and charge imbalance in trilayer Bi2223 using laser-ARPES, establishing an electronic phase diagram.

Findings

Charge imbalance between CuO2 planes increases with doping.

Distinct kink energies observed in nodal band dispersions.

Nodal Fermi velocity remains nearly constant across doping levels.

Abstract

The doping evolution of the nodal electron dynamics in the trilayer cuprate superconductor Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10+\delta}$ (Bi2223) is investigated using high-resolution laser-based angle-resolved photoemission spectroscopy (ARPES). Bi2223 single crystals with different doping levels are prepared by controlled annealing which cover the underdoped, optimally-doped and overdoped regions. The electronic phase diagram of Bi2223 is established which describes the T$_\mathrm{c}$ dependence on the sample doping level. The doping dependence of the nodal Fermi momentum for the outer (OP) and inner (IP) CuO$_2$ planes is determined. Charge distribution imbalance between the OP and IP CuO$_2$ planes is quantified, showing enhanced disparity with increasing doping. Nodal band dispersions demonstrate a prominent kink at $\sim$94$\,$meV in the IP band, attributed to the unique Cu coordination in the IP plane, while a weaker $\sim$60$\,$meV kink is observed in the OP band. The nodal Fermi velocity of both OP and IP bands is nearly constant at $\sim$1.62$\,$eV\r{A} independent of doping. These results provide important information to understand the origin of high T$_\mathrm{c}$ and superconductivity mechanism in high temperature cuprate superconductors.