Coexistence of superconductivity and charge-density-wave domain in $1T$-Fe$_x$Ta$_{1-x}$SSe

TL;DR

This study explores how Fe substitution in $1T$-TaSSe affects superconductivity and charge-density-wave order, revealing coexistence of superconductivity with CDW domains and the transition to Anderson localization at higher doping levels.

Contribution

It demonstrates the suppression of CDW and superconductivity through Fe doping and shows their coexistence in $1T$-TaSSe, supported by experimental and DFT calculations.

Findings

Superconductivity is suppressed by Fe substitution up to x=0.03.

CDW order disappears with Fe doping, but superconductivity coexists with CDW domains.

Higher Fe doping leads to Anderson localization due to increased disorder.

Abstract

A series of $1T$-Fe$_x$Ta$_{1-x}$SSe (0 $\leq x \leq$ 0.1) single crystals was fabricated via the chemical-vapor-transport (CVT) method and investigated by structure, transport, and magnetic measurements along with the density-functional-theory (DFT) calculations. The superconductivity (SC) in parent $1T$-TaSSe can be gradually suppressed by Fe-substitution ($x\leq0.03$), accompanied by the disappearance of charge-density-wave (CDW). DFT calculations show that the Fe-substitution effectively inhibits the CDW superstructure and thereby the CDW domains are destroyed. With further increasing $x$ ($x>0.03$), the disorder-induced scattering increases, and the system enters into the possible Anderson localization (AL) state. Our results prove the SC develops in the CDW phase and coexists with the CDW domain in $1T$-TaSSe system.