Transition metal dichalcogenides host a wide variety of lattice and electronic structures, as well as corresponding exotic physical properties, especially under certain tuning conditions. Here, we are the first to report the observation of pressure-induced three superconducting transitions in TaTe2, a charge density wave (CDW) - bearing layered transition-metal dichalcogenide that is metallic but not superconducting at ambient pressure. We find that its CDW state can be easily suppressed upon increasing pressure up to ~ 1 GPa. A superconducting state then emerges from the suppressed CDW state and persists to the pressure about 7 GPa. Unexpectedly, another superconducting state appears at ~ 11 GPa within the same monoclinic (M) structure of its ambient-pressure one. Upon further compression to 21 GPa, a third superconducting state with higher Tc appears from a high-pressure (HP) phase. Our experimental results suggest that the pressure-induced three superconducting transitions in TaTe2 are respectively driven by the suppression of the CDW state, the change of the angle in the M phase and the transition of M-to-HP phase. These results demonstrate not only the versatile nature of this correlated electron system, but also the first experimental example that shows the pressure-induced evolution from a CDW state to three superconducting states driven by different mechanisms.
@article{arxiv.1704.08106,
title = {Observation of three superconducting transitions in the pressurized CDW-bearing compound TaTe2},
author = {Jing Guo and Huixia Luo and Huaixin Yang and Linlin Wei and Honghong Wang and Wei Yi and Yazhou Zhou and Zhe Wang and Shu Cai and Shan Zhang and Xiaodong Li and Yanchun Li and Jing Liu and Ke Yang and Aiguo Li and Jianqi Li and Qi Wu and Robert J Cava and Liling Sun},
journal= {arXiv preprint arXiv:1704.08106},
year = {2023}
}