Nearly isotropic superconductivity in the layered Weyl semimetal WTe2 at 98.5 kbar

Abstract

The layered transition metal dichalcogenide WTe2 has recently attracted significant attention due to the discovery of an extremely large magnetoresistance, a predicted type-II Weyl semimetallic state, and a pressure-induced superconducting state. By a careful measurement of the superconducting upper critical fields as a function of the magnetic field angle at a pressure as high as 98.5 kbar, we provide the first detailed examination of the dimensionality of the superconducting condensate in WTe2. Despite the layered crystal structure, the upper critical field exhibits a negligible field anisotropy. The angular dependence of the upper critical field can be satisfactorily described by the anisotropic mass model from 2.2 K (T/Tc∼0.67) to 0.03 K (T/Tc∼0.01), with a practically identical anisotropy factor γ∼1.7. The temperature dependence of the upper critical field, determined for both H⊥ab and H∥ab, can be understood by a conventional orbital depairing mechanism. A comparison of the upper critical fields along the two orthogonal field directions results in the same value of γ∼1.7, leading to a temperature-independent anisotropy factor from near Tc to <0.01Tc. Our findings thus identify WTe2 as a nearly isotropic superconductor, with an anisotropy factor among one of the lowest known in superconducting transition metal dichalcogenides.

Source-reported materials — not catalogue approval

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