论文标题
重新访问带有等离子和等离子类吸收材料的纵向光学模式-Srtio $ _3 $和$β$ -GA $ -GA $ _2 $ o $ $ _3 $
Revisiting longitudinal optical modes in materials with plasmon and plasmon-like absorptions -- SrTiO$_3$ and $β$-Ga$_2$O$_3$
论文作者
论文摘要
我们研究了具有等离子体或等离子类的声子模式和其他声子模式的化合物中的纵向光学（LO）模式。当等离子体或等离子体样模式的振荡器强度逐渐增加时，将对模式进行重新排序。由于LO模式越过横向光学（TO）模式的位置，因此在具有正交或更高对称性的晶体中不可能进行重新排序。在此模式杂交期间，等离子体或等离子体样LO模式逐渐成为最初的LO模式，而后者则变为前者。结果，形成了内部（LO-TO）和外部（TO-LO）模式对。该过程一直持续到LO振荡器强度如此之高，以至于所有其他声子都被倒置并在等离子体或等离子体样模式的外to-lo模式对内形成lo-to对。这些见解可以很容易地转移到其他半导体或带有RESTSTRAHLEN频段的许多模式材料上，并允许简单的模式分配。这些模式分配将有助于理解这些材料结构层的表面模式的性质，以应用基于表面的基于表面的偏振子和基于表面声子极化子的超材料。
We investigate exemplary the longitudinal optical (LO) mode order in compounds with a plasmon or plasmon-like phonon mode and additional phonon modes. When the oscillator strength of the plasmon or plasmon-like mode is gradually increased, a reordering of the modes takes place. Since it is not possible in crystals with orthorhombic or higher symmetry that a LO mode crosses a transverse optical (TO) mode's position, this reordering takes place via mode hybridization. During this mode hybridization, the plasmon or plasmon-like LO mode gradually becomes the originally higher situated LO mode while the latter morphs into the former. As a consequence, an inner (LO-TO) and an outer (TO-LO) mode pair is formed. This process continues until the LO oscillator strength is so high that all other phonons are inverted and form LO-TO pairs within the outer TO-LO mode pair of the plasmon or plasmon-like mode. These insights can be readily transferred to other semiconductors or many mode materials with reststrahlen bands and allow simple mode assignments. These mode assignments will help to understand the nature of surface modes of structured layers of these materials for application of surface plasmon polariton and surface phonon polaritons based metamaterials.
