Ab-initio study of coherent phonons excited by femtosecond laser pulses in Bismuth
Ab-initio study of coherent phonons excited by femtosecond laser pulses in Bismuth
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铋中飞秒激光脉冲激发相干声子的从头算研究
DOI：
10.1117/12.674387
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发表时间：
2006
影响因子：
4.5
通讯作者：
Martin E. Garcia
中科院分区：
文献类型：
--
作者：
E. S. Zijlstra;L. Tatarinova;Martin E. Garcia
利用Born-Oppenheimer近似计算了光激发铋体的势能面。我们确定的情况下，高密度的激发载流子的声子频率和潜在的非谐性。特别地，我们专注于声子模式A1 g和Eg。我们发现强烈软化的A1 g-频率增加激发载流子密度。此外，从分析的晶格运动激发时，我们表明，有A1 g和Eg模式之间的耦合，这是与最近的实验结果相一致。
Using the Born-Oppenheimer approximation we calculate potential energy surfaces of photoexcited Bismuth-bulk. We determine phonon frequencies and potential anharmonicities for the case of high density of excited carriers. In particular, we focus on the phonon modes A1g and Eg. We find strong softening of the A1g-frequency for increasing excited carrier density. Furthermore, from the analysis of the lattice motion upon excitation we show that there is a coupling between the A1g and Eg modes, which is consistent with recent experimental findings.