At low temperature TiSe2 undergoes a charge density wave instability. Superconductivity is stabilized either by pressure or by Cu intercalation. We show that the pressure phase diagram of TiSe2 is well described by first-principles calculations. At pressures smaller than 4 GPa charge density wave ordering occurs, in agreement with experiments. At larger pressures the disappearing of the charge density wave is due to a stiffening of the short-range force-constants and not to the variation of nesting with pressure. Finally we show that the behavior of Tc as a function of pressure is entirely determined by the electron-phonon interaction without need of invoking excitonic mechanisms. Our work demonstrates that phase-diagrams with competing orders and a superconducting dome are also obtained in the framework of the electron-phonon interaction.
@article{arxiv.1104.0492,
title = {Charge density wave and superconducting dome in TiSe2 from electron-phonon interaction},
author = {Matteo Calandra and Francesco Mauri},
journal= {arXiv preprint arXiv:1104.0492},
year = {2015}
}