Transition-metal chalcogenides host various phases of matter, such as charge-density wave (CDW), superconductors, and topological insulators or semimetals. Superconductivity and its competition with CDW in low-dimensional compounds have attracted much interest and stimulated considerable research. Here we report pressure induced superconductivity in a strong spin-orbit (SO) coupled quasi-one-dimensional (1D) transition-metal chalcogenide NbTe4, which is a CDW material under ambient pressure. With increasing pressure, the CDW transition temperature is gradually suppressed, and superconducting transition, which is fingerprinted by a steep resistivity drop, emerges at pressures above 12.4 GPa. Under pressure p = 69 GPa, zero resistance is detected with a transition temperature Tc = 2.2 K and an upper critical field Hc2= 2 T. We also find large magnetoresistance (MR) up to 102\% at low temperatures, which is a distinct feature differentiating NbTe4 from other conventional CDW materials.
@article{arxiv.1804.07448,
title = {Pressure induced superconductivity bordering a charge-density-wave state in NbTe4 with strong spinorbit coupling},
author = {Xiaojun Yang and Yonghui Zhou and Mengmeng Wang and Hua Bai and Xuliang Chen and Chao An and Ying Zhou and Qian Chen and Yupeng Li and Zhen Wang and Jian Chen and Chao Cao and Yuke Li and Yi Zhou and Zhaorong Yang and Zhu-An Xu},
journal= {arXiv preprint arXiv:1804.07448},
year = {2018}
}