Electron-phonon superconductivity and charge density wave instability in the layered titanium-based pnictide BaTi${}_2$Sb${}_2$O

Abstract

I present the results of first principles calculations of the phonon dispersions and electron-phonon coupling for BaTi${}_2$Sb${}_2$O. The phonon dispersions show a weak lattice instability near the zone corners that leads to a charge-density wave phase. The calculations of the electron-phonon coupling reveal strong coupling, especially to the in-plane Ti modes. The total coupling is large enough to readily explain the superconductivity in this compound. As the Fermi surfaces are disconnected with different orbital character weights, this compound is likely to host a multiband superconductivity.

Added the phonon dispersions and electron-phonon coupling for the distorted structure

References in corpus (3)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Ba1-xNaxTi2Sb2O (0.0 <= x <= 0.33): A Layered Titanium-based Pnictide Oxide Superconductor
• Electronic structure, disconnected Fermi surfaces and antiferromagnetism in the layered pnictide superconductor Na${}_x$Ba${}_{1-x}$Ti${}_2$Sb${}_2$O

Cited by in corpus (1)

• Superconductivity, charge- or spin-density wave, and metal-nonmetal transition in BaTi${}_2$(Sb${}_{1-x}$Bi${}_x$)${}_2$O