Pressure dependence of the charge-density-wave and superconducting states in GdTe$_3$, TbTe$_3$ and DyTe$_3$

TL;DR

This study investigates how pressure affects charge-density-wave states and induces superconductivity in GdTe3, TbTe3, and DyTe3, revealing suppression of CDWs and emergence of superconductivity with increasing pressure.

Contribution

It provides the first detailed pressure-dependent phase diagrams of these rare-earth tellurides, showing the interplay between CDWs and superconductivity.

Findings

Charge-density-waves are suppressed at high pressure.

Superconductivity emerges as CDWs are suppressed.

High-pressure phase shows enhanced superconducting properties.

Abstract

We present electrical resistivity and ac-susceptibility measurements of GdTe$_3$, TbTe$_3$ and DyTe$_3$ performed under pressure. An upper charge-density-wave (CDW) is suppressed at a rate of $\mathrm{d}T_{\mathrm{CDW,1}}/\mathrm{d}P$ = $-$85 K/GPa. For TbTe$_3$ and DyTe$_3$, a second CDW below $T_{\mathrm{CDW,2}}$ increases with pressure until it reaches the $T_{\mathrm{CDW,1}}$($P$) line. For GdTe$_3$, the lower CDW emerges as pressure is increased above $\sim$ 1 GPa. As these two CDW states are suppressed with pressure, superconductivity (SC) appears in the three compounds at lower temperatures. Ac-susceptibility experiments performed on TbTe$_3$ provide compelling evidence for bulk SC in the low-pressure region of the phase diagram. We provide measurements of superconducting critical fields and discuss the origin of a high-pressure superconducting phase occurring above 5 GPa.