Superconductivity of transition metal dichalcogenide 1T-TiTe2 under high pressure was investigated by the first-principles calculations. Our results show that the superconductivity of 1T-TiTe2 exhibits very different behavior under the hydrostatic and uniaxial pressure. The hydrostatic pressure is harmful to the superconductivity, while the uniaxial pressure is beneficial to the superconductivity. Superconducting transition temperature TC at ambient pressure is 0.73 K, and it reduces monotonously under the hydrostatic pressure to 0.32 K at 30 GPa. While the TC increases dramatically under the uniaxial pressure along c axis. The established TC of 6.34 K under the uniaxial pressure of 17 GPa, below which the structural stability maintains, is above the liquid helium temperature of 4.2 K. The increase of density of states at Fermi level, the redshift of F(ω)/α2F(ω) and the softening of the acoustic modes with pressure are considered as the main reasons that lead to the enhanced superconductivity under uniaxial pressure. In view of the previously predicted topological phase transitions of 1T-TiTe2 under the uniaxial pressure [Phys. Rev. B 88, 155317 (2013)], we consider 1T-TiTe2 as a possible candidate in transition metal chalcogenides for exploring topological superconductivity.
@article{arxiv.1701.01798,
title = {Manipulating superconductivity of $1T$-TiTe$_2$ by high pressure},
author = {R. C. Xiao and W. J. Lu and D. F. Shao and J. Y. Li and M. J. Wei and H. Y. Lv and P. Tong and X. B. Zhu and Y. P. Sun},
journal= {arXiv preprint arXiv:1701.01798},
year = {2017}
}