Ab initio analysis of plasmon dispersion in sodium under pressure

作者：Ibanez Azpiroz Julen^*; Rousseau Bruno; Eiguren Asier; Bergara Aitor

来源：Physical Review B, 2014, 89(8): 085102.

DOI：10.1103/PhysRevB.89.085102

We present an ab initio study of the electronic response function of sodium in its five known metallic phases from 0 to 180 GPa at room temperature. The considered formalism is based on a interpolation scheme within time-dependent density functional theory that uses maximally localized Wannier functions, providing an accurate sampling of the reciprocal space. Besides showing an excellent agreement with inelastic x-ray scattering experiments [Phys. Rev. Lett. 107, 086402 (2011), Proc. Natl. Acad. Sci. USA 108, 20434 (2011)], our calculations reveal that the drastic decrease of the optical reflectivity measured in the high pressure phases oP8 and tI19 [Proc. Natl. Acad. Sci. USA 106, 6525 (2009)] is associated with a new low-energy plasmon arising from collective interband excitations. Additionally, our calculations predict the existence of an anisotropic interband plasmon in the stability pressure range of fcc Na (65 to 105 GPa).

• 出版日期2014-2-5