arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.05359cond-mat.mtrl-sci
收藏

利用快电子探测和操控各向异性材料中的体表面声子极化子

Probing and steering bulk and surface phonon polaritons in uniaxial materials using fast electrons: hexagonal boron nitride

Materials Physics Center, CSIC-UPV/EHU(材料物理中心,CSIC-UPV/EHU);CIC NanoGUNE BRTA(纳米技术研究中心 NanoGUNE);Department of Electricity and Electronics, EHU/UPV(电气与电子工程系,巴斯克国立大学);IKERBASQUE, Basque Foundation for Science(伊卡巴斯基克,巴斯克科学基金会);Donostia International Physics Center DIPC(圣塞巴斯蒂安国际物理中心)

C. Maciel-Escudero, Andrea Konečná, Rainer Hillenbrand, Javier Aizpurua

AI总结:

研究快电子与各向异性材料中极化子模式的耦合机制,揭示电子速度和光轴角度对体表面声子极化子激发的影响,为操控极化子波传播提供新方法。

摘要:

我们理论描述了快电子如何通过分析电子能量损失(EEL)光谱与各向异性材料中的极化子模式耦合。我们展示,在具有双曲色散的各向异性介质中,快电子穿过体积或沿材料与真空界面之间无限界面时,可以激发体模和表面模。有趣的是,与各向同性材料中的激发不同,快电子在各向异性介质外部也能激发体模。我们通过代表性的各向异性材料六方氮化硼验证了我们的发现。我们表明,体和表面声子极化子的激发强烈依赖于电子速度,并高度依赖于电子束轨迹与材料光轴之间的角度。我们的工作为理解快电子束激发的各向异性材料中体和表面极化子提供了系统研究,并为通过改变电子速度和方向来操控极化子波的传播提供了方法。

英文摘要:

We theoretically describe how fast electrons couple to polaritonic modes in uniaxial materials by analyzing the electron energy loss (EEL) spectra. We show that in the case of an uniaxial medium with hyperbolic dispersion, bulk and surface modes can be excited by a fast electron traveling through the volume or along an infinite interface between the material and vacuum. Interestingly, and in contrast to the excitations in isotropic materials, bulk modes can be excited by fast electrons traveling outside the uniaxial medium. We demonstrate our findings with the representative uniaxial material hexagonal boron nitride. We show that the excitation of bulk and surface phonon polariton modes is strongly related to the electron velocity and highly dependent on the angle between the electron beam trajectory and the optical axis of the material. Our work provides a systematic study for understanding bulk and surface polaritons excited by a fast electron beam in hyperbolic materials and sets a way to steer and control the propagation of the polaritonic waves by changing the electron velocity and its direction.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑