Quantum oscillation and superconductivity study of the layered Weyl semimetal WTe₂ under pressure

We investigate the electronic properties of transition metal dichalcogenides WTe₂ under pressure. WTe₂ starts to superconduct at ~30 kbar. At 35 kbar, T_c is about 0.95 K. To figure out the relationship between the pressure-induced superconductivity and Fermi surface, we conduct Shubnikov–de Haas quantum oscillation measurements. At ambient pressure, four dominant peaks are observed, whose frequencies are 97 T, 134 T, 150 T and 172 T respectively. By applying pressure, these frequencies and the associated effective masses increase, suggesting the expansion of Fermi surfaces accompanied with enhanced electron-electron correlation. Moreover, we observe a high frequency at ~2000 T and extract a relatively large effective mass m* of 1.8 m_e at 35 kbar. The enhanced correlation under pressure revealed by our quantum oscillation study provides new information on understanding the pressure-induced superconductivity in WTe₂.