Sattar Shahid, Larsson J Andreas
Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå SE-97187, Sweden.
ACS Omega. 2021 Jan 26;6(5):4044-4050. doi: 10.1021/acsomega.0c06043. eCollection 2021 Feb 9.
The possibility to achieve charge-to-spin conversion via Rashba spin-orbit effects provides stimulating opportunities toward the development of nanoscale spintronics. Here, we use first-principles calculations to study the electronic and spintronic properties of TlO/PtS heterostructure, for which we have confirmed the dynamical stability by its positive phonon frequencies. An unexpectedly high binding energy of -0.38 eV per unit cell depicts strong interlayer interactions between TlO and PtS. Interestingly, we discover Rashba spin-splittings (with a large α value) in the valence band of TlO stemming from interfacial spin-orbit effects caused by PtS. The role of van der Waals binding on the orbital rearrangements has been studied using the electron localization function and atomic orbital projections, which explains in detail the electronic dispersion near the Fermi level. Moreover, we explain the distinct band structure alignment in momentum space but separation in real space of TlO/PtS heterostructure. Since two-dimensional (2D) TlO still awaits experimental confirmation, we calculate, for the first time, the Raman spectra of pristine TlO and the TlO/PtS heterostructure and discuss peak positions corresponding to vibrational modes of the atoms. These findings offer a promising avenue to explore spin physics for potential spintronics applications via 2D heterostructures.
通过 Rashba 自旋轨道效应实现电荷到自旋转换的可能性为纳米级自旋电子学的发展提供了令人兴奋的机遇。在此，我们使用第一性原理计算来研究 TlO/PtS 异质结构的电子和自旋电子特性，通过其正的声子频率我们已证实了其动力学稳定性。每单位晶胞 -0.38 eV 的意外高结合能表明 TlO 和 PtS 之间存在强层间相互作用。有趣的是，我们在 TlO 的价带中发现了源于 PtS 引起的界面自旋轨道效应的 Rashba 自旋分裂（具有大的α值）。利用电子定域函数和原子轨道投影研究了范德华键合对轨道重排的作用，这详细解释了费米能级附近的电子色散。此外，我们解释了 TlO/PtS 异质结构在动量空间中独特的能带结构排列但在实空间中分离的现象。由于二维（2D）TlO 仍有待实验证实，我们首次计算了原始 TlO 和 TlO/PtS 异质结构的拉曼光谱，并讨论了与原子振动模式相对应的峰位。这些发现为通过二维异质结构探索自旋物理以用于潜在的自旋电子学应用提供了一条有前景的途径。
