Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Phys Rev Lett. 2013 Sep 20;111(12):126801. doi: 10.1103/PhysRevLett.111.126801. Epub 2013 Sep 17.
Although new spintronic devices based on the giant spin-orbit splitting of single-layer MoS(2) have been proposed, such splitting has not been studied effectively in experiments. This Letter reports the valence band spin-orbit splitting in single-layer MoS(2) for the first time, probed by the triply resonant Raman scattering process. We found that upon 325 nm laser irradiation, the second order overtone and combination Raman modes of single-layer MoS(2) are dramatically enhanced. Such resonant Raman enhancement arises from the electron-two-phonon triple resonance via the deformation potential and Fröhlich interaction. As a sensitive and precise probe for the spin-orbit splitting, the triply resonant Raman scattering will provide a new and independent route to study the spin characteristics of MoS(2).
虽然已经提出了基于单层 MoS(2) 巨大自旋轨道劈裂的新型自旋电子器件，但这种劈裂在实验中尚未得到有效研究。本研究首次通过三共振拉曼散射过程报告了单层 MoS(2) 中的价带自旋轨道劈裂。我们发现，在 325nm 激光辐照下，单层 MoS(2) 的二次谐波和组合拉曼模式显著增强。这种共振拉曼增强源于电子-双声子三共振，通过变形势和 Fröhlich 相互作用。作为自旋轨道劈裂的灵敏和精确探针，三共振拉曼散射将为研究 MoS(2) 的自旋特性提供新的独立途径。
