Fermi Surface and Quasiparticle Excitations of overdoped Tl2Ba2CuO6+d by ARPES

TL;DR

This study uses ARPES to analyze the electronic structure of overdoped Tl2Ba2CuO6+d, revealing a large hole Fermi surface, a tentative d-wave gap, and unusual quasiparticle behavior, contributing to understanding high-T_c superconductivity.

Contribution

It provides new insights into the Fermi surface topology and quasiparticle dynamics in overdoped cuprates, highlighting deviations from behavior in underdoped and optimally doped samples.

Findings

Fermi surface is a single large hole pocket approaching a topological transition.

Superconducting gap shows tentative d_x^2-y^2 symmetry.

Quasiparticle behavior departs from that in less doped cuprates.

Abstract

The electronic structure of the high-T_c superconductor Tl2Ba2CuO6+d is studied by ARPES. For a very overdoped Tc=30K sample, the Fermi surface consists of a single large hole pocket centered at (pi,pi) and is approaching a topological transition. Although a superconducting gap with d_x^2-y^2 symmetry is tentatively identified, the quasiparticle evolution with momentum and binding energy exhibits a marked departure from the behavior observed in under and optimally doped cuprates. The relevance of these findings to scattering, many-body, and quantum-critical phenomena is discussed.