Short-ranged charge density wave and superconductivity in a 1T-NbSeTe crystal

Abstract

Niobium-based dichalcogenides (NbX2, where X=S, Se, Te) exhibit tunable intertwining charge density waves (CDWs) and superconductivity, especially NbSe2 and NbTe2, which have attracted much attention due to their abundant electronic properties. However, the evolution of CDWs and superconductivity from NbSe2 to NbTe2 remains elusive. Here, using ultralow temperature scanning tunneling microscopy and spectroscopy (STM/STS) at 400 mK, we discover local short-range CDW patterns in 1T-NbSeTe, in which the three CDW components are spatially decoupled, indicating that the CDW in 1T-NbSeTe resides in a melted state of the 3 × 3 CDW of 2H−NbSe2 and 3 × 1 CDW orders of 1T″−NbTe2. The short-range CDWs coexist with the superconductivity below a critical temperature of ∼1.5 K and an upper critical field of ∼1.7 T. The scaling relationship between the zero-energy density of states and the superconducting gap across a single vortex indicates that 1T-NbSeTe is a dirty superconductor. These findings provide valuable insights into the doping induced CDW melting and superconducting states in transition metal dichalcogenides.

Source-reported materials — not catalogue approval

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