Anomalous dispersion of the acoustic mode in liquid Bi

作者:Inui M*; Kajihara Y; Munejiri S; Hosokawa S; Chiba A; Ohara K; Tsutsui S; Baron A Q R
来源:Physical Review B, 2015, 92(5): 054206.
DOI:10.1103/PhysRevB.92.054206

摘要

Inelastic x-ray scattering measurements on liquid Bi were carried out. Prominent acoustic mode excitations were observed in the dynamic structure factor to beyond 12 nm(-1), which resolves previously conflicting results as to their presence beyond 6 nm(-1). We find the dispersion curve of the excitation energy with momentum transfer is nearly flat from 7 to 15 nm(-1) consistent with ab initio calculations of liquid Bi [J. Souto et al., Phys. Rev. B 81, 134201 (2010)]. Our ab initio and classical molecular dynamics simulations suggest that a long-range force is needed to reproduce the flatness of the dispersion curve, and the long-range force is correlated with a local structure consisting of shorter and longer bonds in the liquid.

  • 出版日期2015-8-25
  • 单位RIKEN