Pressure-induced semimetal to superconductor transition in a three-dimensional topological material ZrTe5

TL;DR

This study reveals a pressure-induced transition in ZrTe5 from a topological semimetal to a superconductor, with multiple phases and structural changes identified through experiments and theoretical analysis.

Contribution

It demonstrates the emergence of superconductivity in ZrTe5 under high pressure and links it to structural phase transitions, providing insights into topological materials under extreme conditions.

Findings

Superconductivity appears above 6.2 GPa after suppressing resistance anomaly.

Maximum Tc of 6.0 K observed at pressures above 21.2 GPa.

Structural phase transition from Cmcm to C2/m and P-1 phases correlates with superconducting behavior.

Abstract

As a new type of topological materials, ZrTe5 shows many exotic properties under extreme conditions. Utilizing resistance and ac magnetic susceptibility measurements under high pressure, while the resistance anomaly near 128 K is completely suppressed at 6.2 GPa, a fully superconducting transition emerges surprisingly. The superconducting transition temperature Tc increases with applied pressure, and reaches a maximum of 4.0 K at 14.6 GPa, followed by a slight drop but remaining almost constant value up to 68.5 GPa. At pressures above 21.2 GPa, a second superconducting phase with the maximum Tc of about 6.0 K appears and coexists with the original one to the maximum pressure studied in this work. In situ high-pressure synchrotron X-ray diffraction and Raman spectroscopy combined with theoretical calculations indicate the observed two-stage superconducting behavior is correlated to the structural phase transition from ambient Cmcm phase to high-pressure C2/m phase around 6 GPa, and to a mixture of two high-pressure phases of C2/m and P-1 above 20 GPa. The combination of structure, transport measurement and theoretical calculations enable a complete understanding of the emerging exotic properties in three-dimensional topological materials happened under extreme environments.