Pressure-induced superconductivity in a three-dimensional topological material ZrTe ₅

Abstract

As a new type of topological materials, ZrTe 5 shows many exotic properties under extreme conditions. Using 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. The superconducting transition temperature T c 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 T c 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 3D topological materials under extreme environments.high pressure | Dirac semimetals | superconductivity | synchrotron X-ray diffraction S ince the first report of topological insulator, an extensive attention in recent years has been focused on newly emergent Dirac materials including topological insulators (1-3), Dirac semimetals (4, 5), and Weyl semimetals (5-7) for their unique quantum phenomena. ZrTe 5 has been studied for a long time due to its large thermoelectric power (8, 9), resistivity anomaly (10, 11), and large positive magnetoresistance (12). Recent theoretical works (13,14) have proposed that single-layer ZrTe 5 is a large gap quantum spin hall insulator, but the bulk ZrTe 5 behaves between the strong and weak topological insulator. These predictions spark the renewed interest in the investigation of its Dirac and topological characters. Indeed, the magnetotransport experiments (15) have observed the chiral magnetic effect, both angle-resolved photoemission spectroscopy (15) and magneto-infrared spectroscopy (16, 17) study show the electronic structure of ZrTe 5 is similar with other three-dimensional (3D) Dirac semimetals like Na 3 Bi (18-20) and Cd 3 As 2 (21-25). These results suggest that ZrTe 5 is a very promising system that hosts topological properties and might help to pave a new way for further experimental studies of topological phase transitions.As one of the fundamental state parameters, high pressure is an effective, clean way to tune lattice as well as electronic states, especially in quantum states (26)(27)(28). In this work, by performing resistance and ac magnetic susceptibility measurements on ZrTe 5 single crystal at various pressures up to 68.5 GPa, a superconducting transition at 1.8 K was first noticed at a pressure of 6.2 GPa. It was interesting to notice that the occurrence of the metallic pha...

Pressure-driven superconductivity in the transition-metal pentatellurideHfTe5

“…With increasing P, the temperature of resistivity peak increases to ~110 K at P  5.0 GPa, but then shifts back towards lower temperatures at further P increase. A similar pressure dependence of the resistivity anomaly is observed for ZrTe5 19 . This obviously common pressure behavior of the two pentatellurides is different from that of chalcogenides exhibiting a CDW (CDW transitions are typically suppressed by application of pressure) 28 .…”

“…In contrast, we do not observe any indication of a second superconducting phase analogous to the SC-II phase in ZrTe5 19 . Considering the close similarities in ambient-pressure properties and the pressure-driven behavior of both pentatellurides, it might be supposed that the SC-II phase in ZrTe2 is rather a metastable state characteristic only for this compound.…”

“…As a powerful tool to tune the electronic properties, pressure was also applied to these compounds. Recently, a pressure-induced semimetal to superconductor transition was observed in ZrTe5 19 , while the behavior of HfTe5 under pressure is yet to be explored.…”

Disruption of the Accidental Dirac Semimetal State in ZrTe5 under Hydrostatic Pressure

“…Recently, a pressure-induced semimetal to superconductor transition was observed in ZrTe 5 at 6.2 GPa [27]. However, no quantum oscillation is observed in their pressure study, which is likely due to the pressure inhomogeneity.…”

Concurrence of superconductivity and structure transition in Weyl semimetal TaP under pressure

“…Therefore, it is natural that the MR decreases when increasing pressure. Superconductivity has been induced in some materials with giant MR 23,24,[36][37][38] when pressure is applied. In the following, we will show that superconducting behavior has also been detected in TaP with further increasing pressure.…”