Superconductivity and Charge Density Wave in ZrTe$_{3-x}$Se$_{x}$

TL;DR

This study shows that Se doping suppresses charge density wave order and induces superconductivity in ZrTe3, with a maximum Tc of 4 K, revealing a complex interplay between these two electronic states.

Contribution

It demonstrates the emergence of superconductivity upon Se doping in ZrTe3 as CDW order is suppressed, providing new insights into their coexistence and competition.

Findings

Superconductivity appears with Se doping when CDW order is suppressed.

Maximum Tc of 4 K observed for 0.04 ≤ x ≤ 0.07 in ZrTe3-xSex.

High-temperature resistivity is linear and dominated by local CDW fluctuations.

Abstract

Charge density wave (CDW), the periodic modulation of the electronic charge density, will open a gap on the Fermi surface that commonly leads to decreased or vanishing conductivity. On the other hand superconductivity, a commonly believed competing order, features a Fermi surface gap that results in infinite conductivity. Here we report that superconductivity emerges upon Se doping in CDW conductor ZrTe$_{3}$ when the long range CDW order is gradually suppressed. Superconducting critical temperature $T_c(x)$ in ZrTe$_{3-x}$Se$_x$ (${0\leq}x\leq0.1$) increases up to 4 K plateau for $0.04$$\leq$$x$$\leq$$0.07$. Further increase in Se content results in diminishing $T_{c}$ and filametary superconductivity. The CDW modes from Raman spectra are observed in $x$ = 0.04 and 0.1 crystals, where signature of ZrTe$_{3}$ CDW order in resistivity vanishes. The electronic-scattering for high $T_{c}$ crystals is dominated by local CDW fluctuations at high temperures, the resistivity is linear up to highest measured $T=300K$ and contributes to substantial in-plane anisotropy.