Surface Superconductivity in the type II Weyl Semimetal TaIrTe4

TL;DR

This paper reports the discovery of surface superconductivity in the Weyl semimetal TaIrTe4, which exhibits unconventional p-wave pairing and occurs in surface states, offering a platform for topological superconductivity and Majorana modes.

Contribution

The study provides the first evidence of surface superconductivity in TaIrTe4, a type II Weyl semimetal, with detailed STM/S and transport measurements confirming its unconventional nature.

Findings

Superconducting gaps observed on the surface of TaIrTe4.

Superconductivity with Tc up to 1.54 K confirmed by transport measurements.

Superconductivity is quasi-one-dimensional and occurs in surface states.

Abstract

The search for unconventional superconductivity in Weyl semimetal materials is currently an exciting pursuit, since such superconducting phases could potentially be topologically nontrivial and host exotic Majorana modes. The layered material TaIrTe4 is a newly predicted time-reversal invariant type II Weyl semimetal with minimum number of Weyl points. Here, we report the discovery of surface superconductivity in Weyl semimetal TaIrTe4. Our scanning tunneling microscopy/spectroscopy (STM/S) visualizes Fermi arc surface states of TaIrTe4 that are consistent with the previous angle-resolved photoemission spectroscopy (ARPES) results. By a systematic study based on STS at ultralow temperature, we observe uniform superconducting gaps on the sample surface. The superconductivity is further confirmed by electrical transport measurements at ultralow temperature, with an onset transition temperature (Tc) up to 1.54 K being observed. The normalized upper critical field h*(T/Tc) behavior and the stability of the superconductivity against the ferromagnet indicate that the discovered superconductivity is unconventional with the p-wave pairing. The systematic STS, thickness and angular dependent transport measurements reveal that the detected superconductivity is quasi-one-dimensional (quasi-1D) and occurs in the surface states. The discovery of the surface superconductivity in TaIrTe4 provides a new novel platform to explore topological superconductivity and Majorana modes.