Pressure induced superconductivity bordering a charge-density-wave state in NbTe₄ with strong spin-orbit coupling

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Transition-metal chalcogenides exhibit diverse quantum phases, including charge-density waves (CDW), superconductivity, and topological states.
• The interplay between superconductivity and CDW order in low-dimensional materials is a key area of research.

Purpose of the Study:

• To investigate the effect of pressure on the quasi-one-dimensional (1D) material NbTe4, known to exhibit CDW order at ambient pressure.
• To explore the emergence of superconductivity and its characteristics under high-pressure conditions.

Main Methods:

• Electrical resistivity measurements under varying hydrostatic pressures.
• Characterization of superconducting transitions via resistivity drops.
• Determination of superconducting transition temperature (Tc) and upper critical field (μ0Hc2).
• Measurement of magnetoresistance (MR) at low temperatures.

Main Results:

• The charge-density wave (CDW) transition temperature in NbTe4 is suppressed with increasing pressure.
• Superconductivity emerges above 12.4 GPa, indicated by a sharp drop in resistivity.
• At 69 GPa, a superconducting transition temperature (Tc) of 2.2 K and an upper critical field (μ0Hc2) of 2 T were observed.
• Large magnetoresistance (MR) reaching 102% was detected at low temperatures.

Conclusions:

• Pressure can induce superconductivity in the CDW material NbTe4, highlighting the competition between these electronic phases.
• The observed large magnetoresistance is a distinguishing feature of pressure-induced superconductivity in NbTe4 compared to conventional CDW materials.