Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 38: Topological Superconductors
TT 38.4: Vortrag
Mittwoch, 18. März 2020, 12:00–12:15, HSZ 103
125Te NMR studies of 1T-MoTe2 under pressure -Towards superconductivity mediated by Weyl Fermions — •H. Yasuoka1, T. Fujii1,2, K.M. Ranjith1, M.O. Ajeesh1, M. Schmidt1, T. Mito2, M. Nicklas1, C. Felser1, A. Mackenzie1, and M. Baenitz1 — 1MPI for Chemical Physics of Solids, D-01187 Dresden, Germany — 2School of Science, University of Hyogo Hyogo, Japan
1T-MoTe2 is claimed to be one of the type-II Weyl semimetals, and has attracted much attention due to its exotic physical properties stemming from the topological (line nodal) band structure where the electron and hole pockets are touching at the Fermi energy. One of the most preeminent features is the occurrence of superconductivity which is stabilized under pressure up to around Tc=7K. In order to understand the superconductivity, we have employed the 125Te NMR technique under pressure (up to 2.17 GPa) and measured the NMR line profile and nuclear magnetic relaxation, determining the Knight shift and low lying magnetic excitations. Using the same NMR tuning circuit, we have also measured the pressure and temperature (T) dependences of the resonant frequency, and extracted the T-dependence of the upper critical field Hc2. The results are not in accord with simple WHH model, but are well fit to an empilical formula, Hc2(T)= Hc2(0)[1−T/Tc]α. By doing this, we obtained Hc2(0)=1.50T, Tc= 3.81K, and α=1.1 at 2.17 GPa. A superconducting signature has been observed in K(T) and 1/T1T(T) at around 2.5 K (2.17GPa, 0.46T). We present detailed NMR results and try to explore the superconductivity from the microscopic point of view.