Carrier-induced disordering dynamics in InSb studied with density functional perturbation theory

作     者：P. B. Hillyard D. A. Reis K. J. Gaffney 

作者机构：Department of Chemistry Stanford University Stanford California 94305 USA PULSE Center Stanford Linear Accelerator Center Stanford University Stanford California 94305 USA FOCUS Center Department of Physics and Applied Physics Program University of Michigan Ann Arbor Michigan 48109 USA 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：2008年第77卷第19期

页      面：195213-195213页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

摘      要：Density functional perturbation theory calculations have been utilized to characterize the carrier density dependent phonon dispersion of InSb. Similar to prior theoretical studies of Si, these calculations predict that a shear instability develops in the crystal at a carrier density of 3.7% of the valence electron density and the entire transverse acoustic phonon branch becomes unstable over a narrow carrier density range of roughly 1%. Unlike calculations for Si, the shear instability appears first at the X point, rather than the L point. We utilize these calculations to interpret recent ultrafast x-ray diffraction measurements of laser-induced disordering in InSb and find that the time scale and laser fluence dependence of the measured disordering dynamics are consistent with these theoretical predictions. The calculations, however, do not reproduce the experimental anisotropy in the root-mean-square displacement.