Yanson point-contact spectroscopy of Weyl semimetal WTe ₂

Abstract

We carried out point contact (PC) investigation of WTe2 single crystals. We measured Yanson PC spectra (d 2 V/dI 2 ) of the electron-phonon interaction (EPI) in WTe2. The PC spectra demonstrate a main phonon peak around 8 meV and a shallow second maximum near 16 meV. Their position is in line with the calculation of the EPI spectra of WTe2 in the literature, albeit phonons with higher energy are not resolved in our PC spectra. An additional contribution to the spectra is present above the phonon energy, what may be connected with the peculiar electronic band structure and need to be clarified. We detected tiny superconducting features in d 2 V/dI 2 close to zero bias, which broadens by increasing temperature and blurs above 6K. Thus, (surface) superconductivity may exist in WTe2 with a topologically nontrivial state. We found a broad maximum in dV/dI at large voltages (>200 mV) indicating change of conductivity from metallic to semiconducting type. The latter might be induced by the high current density (~10 8 A/cm 2 ) in the PC and/or local heating, thus enabling the manipulation of the quantum electronic states at the interface in the PC core.

Superconducting properties of MoTe2 from ab initio anisotropic Migdal-Eliashberg theory

“…Similar to the sister compound tungsten ditelluride (WTe 2 ) 1-3 , MoTe 2 displays large non-saturating magnetoresistance [4][5][6] and pressure-driven superconductivity [7][8][9][10][11] , and it is predicted to be a type-II Weyl semimetal [12][13][14][15][16] . Since MoTe 2 is a prime candidate for realizing topological superconductivity and Marjorana fermions 10,11,[17][18][19][20] , it is important to understand the interplay between the superconducting pairing mechanism, the Fermi surface (FS) topology, and the structural phase transition under applied pressure.…”

Transverse conductance in a three-dimensional Weyl semimetal and Weyl superconductor hybrid under a strong magnetic field

“…Besides UPt 3 , the unconventional superconductivity is also discovered by hard point contact on the WSM TaAs crystals [16,17]. Experimentally, the superconducting states in the WSM have also been studied in other SWSMs, such as MoTe 2 , WTe 2 , TaP, and TaIrTe 4 [18][19][20][21][22][23].…”

Photonic spin Hall effect on the surfaces of type-I and type-II Weyl semimetals

“…Among the research on topological optics, optical conductivity is a key parameter to control and ameliorate the PSHE occurring at a topological interface [30][31][32][33]. However, most of the previous studies do not involve the effects of tilt of Weyl nodes and chemical potential on the complex optical conductivity matrices of WSMs for all frequency ranges [12,[33][34][35]. Therefore, modifying and/or manipulating the PSHE via controlling the tilt and impurity in WSMs, to the best of our knowledge, have not yet been reported so far.…”