Bryk Taras, Demchuk Taras, Wax Jean-François, Jakse Noël
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Street, UA-79011 Lviv, Ukraine. Lviv Polytechnic National University, UA-79013 Lviv, Ukraine.
J Phys Condens Matter. 2020 May 1;32(18):184002. doi: 10.1088/1361-648X/ab6a31.
Collective dynamics of metallic melts at high pressures is one of the open issues of condensed matter physics. By means of ab initio molecular dynamics simulations, we examine features of dispersions of collective excitations through transverse current spectral functions, as a function of pressure. Typical metallic melts, such as Li and Na monovalent metals as well as Al, Pb and In polyvalent metals are considered. We firmly establish the emergence of a second branch of high-frequency transverse modes with pressure in these metals, that we associate with the pronounced high-frequency shoulder in the vibrational density of states. Similar correlation also exist with the low frequency modes. The origin of the pressure-induced evolution of transverse excitations in liquid metals is discussed.
高压下金属熔体的集体动力学是凝聚态物理的开放性问题之一。通过从头算分子动力学模拟，我们根据压力研究了通过横向电流谱函数的集体激发色散特征。考虑了典型的金属熔体，如锂和钠等单价金属以及铝、铅和铟等多价金属。我们明确证实了这些金属中随着压力出现了高频横向模式的第二个分支，我们将其与振动态密度中明显的高频肩部联系起来。低频模式也存在类似的相关性。讨论了液态金属中横向激发的压力诱导演化的起源。
