Superconductivity Observed in Tantalum Polyhydride at High Pressure

TL;DR

This paper reports the experimental discovery of superconductivity in tantalum polyhydride at high pressure, with a transition temperature of around 30 K, marking the first such observation in a transition metal hydride of the VB group.

Contribution

It provides the first experimental evidence of superconductivity in tantalum polyhydride, synthesized at high pressure and temperature conditions, expanding the understanding of hydride superconductors.

Findings

Superconductivity observed at ~30 K in TaH3 at 197 GPa.

Superconducting transition shifts to lower temperatures under magnetic fields.

Estimated upper critical field is ~20 T, with a coherence length of ~40 Å.

Abstract

We report experimental discovery of tantalum polyhydride superconductor. It was synthesized at high pressure and high temperature conditions using diamond anvil cell combined with in-situ high pressure laser heating techniques. The superconductivity was investigated via resistance measurements at pressures. The highest superconducting transition temperature Tc was found to be ~30 K at 197 GPa in the sample that was synthesized at the same pressure with ~2000 K heating. The transitions are shifted to low temperature upon applying magnetic fields that supports the superconductivity nature. The upper critical field at zero temperature {\mu}0Hc2(0) of the superconducting phase is estimated to be ~20 T that corresponds to GL coherent length ~40 angstroms. Our results suggest that the superconductivity may arise from I-43d phase of TaH3. It is, for the first time to our best knowledge, experimental realization of superconducting hydrides for the VB group of transitional metals.