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arXiv · 1104.0492

Charge density wave and superconducting dome in TiSe2 from electron-phonon interaction

Matteo Calandra·Francesco Mauri
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Abstract

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.

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Matteo Calandra, Francesco Mauri. 2011-04-04. Charge density wave and superconducting dome in TiSe2 from electron-phonon interaction. https://doi.org/10.1103/physrevlett.106.196406

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