论文标题
SNTE和PBTE中的异常横向视听子 - 重新审视
Anomalous transverse optic phonons in SnTe and PbTe -- revisited
论文作者
论文摘要
与使用非弹性中子散射和Ab-Initio晶格动力学计算相比，我们介绍了SNTE中软横向光学声子模式的研究。与以前的报告相反，我们的计算预测，SNTE中的软模式具有与PBTE中的质量分布非常不对称的光谱分布。在实验上，我们发现，在SNTE和PBTE的中子散射光谱中，声子峰的总能量宽度是可比的。我们观察到pbte中的众所周知的双峰式签名，甚至下降到$ t $ = 5 k，纯粹基于声子散射，质疑其提议的起源。 PBTE中初期的铁电跃迁的接近可能在当前模型中不包括重要作用。
We present a study of the soft transverse optic phonon mode in SnTe in comparison to the corresponding mode in PbTe using inelastic neutron scattering and ab-initio lattice dynamical calculations. In contrast to previous reports our calculations predict that the soft mode in SnTe features a strongly asymmetric spectral weight distribution qualitatively similar to that found in PbTe. Experimentally, we find that the overall width in energy of the phonon peaks is comparable in our neutron scattering spectra for SnTe and PbTe. We observe the well-known double-peak-like signature of the TO mode in PbTe even down to $T$ = 5 K questioning its proposed origin purely based on phonon-phonon scattering. The proximity to the incipient ferroelectric transition in PbTe likely plays an important role not included in current models.
