论文标题
通过准颗粒干扰成像确定石墨烯中的自旋轨道耦合
Determining spin-orbit coupling in graphene by quasiparticle interference imaging
论文作者
论文摘要
在石墨烯中诱导和控制自旋轨道耦合（SOC）是创建物质拓扑状态和实现自旋设备的关键。将石墨烯放置在过渡金属二进制基础上是实现此目标的最成功的策略，但是就诱导的SOC的性质和大小尚无共识。在这里，我们表明，通过对扫描隧道显微镜进行成像quasiparticle干扰，可以使用wse $ _2 $异质结构中的反向散射的存在来探测其强度。 A detailed theoretical analysis of the Fourier transform of quasiparticle interference images reveals that the induced SOC consists of a valley-Zeeman ($λ_{\text{vZ}}\approx 2$ meV) and a Rashba ($λ_\text{R}\approx 15$ meV) term, one order of magnitude larger than what theory predicts, but in excellent agreement with earlier transport experiments.我们分析的有效性通过在对称考虑因素上预期的30度扭角异质结构上的测量结果证实。我们的结果证明了通过成像准粒子干扰来定量确定SOC的可行策略。
Inducing and controlling spin-orbit coupling (SOC) in graphene is key to create topological states of matter, and for the realization of spintronic devices. Placing graphene onto a transition metal dichalcogenide is currently the most successful strategy to achieve this goal, but there is no consensus as to the nature and the magnitude of the induced SOC. Here, we show that the presence of backscattering in graphene-on-WSe$_2$ heterostructures can be used to probe SOC and to determine its strength quantitatively, by imaging quasiparticle interference with a scanning tunneling microscope. A detailed theoretical analysis of the Fourier transform of quasiparticle interference images reveals that the induced SOC consists of a valley-Zeeman ($λ_{\text{vZ}}\approx 2$ meV) and a Rashba ($λ_\text{R}\approx 15$ meV) term, one order of magnitude larger than what theory predicts, but in excellent agreement with earlier transport experiments. The validity of our analysis is confirmed by measurements on a 30 degree twist angle heterostructure that exhibits no backscattering, as expected from symmetry considerations. Our results demonstrate a viable strategy to determine SOC quantitatively by imaging quasiparticle interference.
