Mongan Sean, Huang Zengye, Datta Trinanjan, Nomura Takuji, Yao Dao-Xin
Department of Chemistry and Physics, Augusta University, 1120 15th Street, Augusta, Georgia, 30912, USA.
State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou, 510275, China.
Sci Rep. 2019 Sep 4;9(1):12771. doi: 10.1038/s41598-019-49157-2.
The control and detection of crystallographic chirality is an important and challenging scientific problem. Chirality has wide ranging implications from medical physics to cosmology including an intimate but subtle connection in magnetic systems, for example MnFeSi. X-ray diffraction techniques with resonant or polarized variations of the experimental setup are currently utilized to characterize lattice chirality. We demonstrate using theoretical calculations the feasibility of indirect K -edge bimagnon resonant inelastic X-ray scattering (RIXS) spectrum as a viable experimental technique to distinguish crystallographic handedness. We apply spin wave theory to the recently discovered √5 × √5 vacancy ordered chalcogenide RbFeSe for realistic X-ray experimental set up parameters (incoming energy, polarization, Bragg angle, and experimental resolution) to show that the computed RIXS spectrum is sensitive to the underlying handedness (right or left) of the lattice. A Flack parameter definition that incorporates the right- and left- chiral lattice RIXS response is introduced. It is shown that the RIXS response of the multiband magnon system RbFeSe arises both from inter- and intra- band scattering processes. The extinction or survival of these RIXS peaks are sensitive to the underlying chiral lattice orientation. This in turn allows for the identification of the two chiral lattice orientations.
晶体手性的控制与检测是一个重要且具有挑战性的科学问题。手性具有广泛的影响，从医学物理到宇宙学，包括在磁性系统（例如MnFeSi）中存在紧密但微妙的联系。目前利用实验装置的共振或偏振变化的X射线衍射技术来表征晶格手性。我们通过理论计算证明了间接K边双磁振子共振非弹性X射线散射（RIXS）光谱作为区分晶体手性的可行实验技术的可行性。我们将自旋波理论应用于最近发现的√5×√5空位有序硫族化合物RbFeSe，针对实际的X射线实验设置参数（入射能量、偏振、布拉格角和实验分辨率），以表明计算出的RIXS光谱对晶格的潜在手性（右手或左手）敏感。引入了一种结合右手和左手手性晶格RIXS响应的弗拉克参数定义。结果表明，多带磁振子系统RbFeSe的RIXS响应既来自带间散射过程，也来自带内散射过程。这些RIXS峰的消光或存在对潜在的手性晶格取向敏感。这反过来又允许识别两种手性晶格取向。
