Superconductivity in Cu$_{x}$IrTe$_{2}$ induced by interlayer hybridization

TL;DR

This study investigates how interlayer hybridization in Cu$_{x}$IrTe$_{2}$ influences its electronic structure and induces superconductivity by suppressing structural distortion and stabilizing a trigonal phase.

Contribution

It demonstrates that interlayer hybridization and a balance of Te-Te interactions drive the structural transition and superconductivity in Cu$_{x}$IrTe$_{2}$, supported by experimental and first-principles data.

Findings

Cu-intercalation suppresses monoclinic distortion

Superconductivity emerges in the trigonal phase

Multiband electronic structure with hole and electron carriers

Abstract

The change in the electronic structure of layered Cu$_{x}$IrTe$_{2}$ has been characterized by transport and spectroscopic measurements, combined with first-principles calculations. The Cu-intercalation suppresses the monoclinic distortion, giving rise to the stabilization of the trigonal phase with superconductivity. Thermopower and Hall resistivity measurements suggest the multiband nature with hole and electron carriers for this system, which is masked by the predominance of the hole carriers enhanced by the interlayer hybridization in the trigonal phase. Rather than the instability of Ir $d$ band, a subtle balance between the interlayer and intralayer Te-Te hybridizations is proposed as a main factor dominating the structural transition and the superconductivity.