论文标题
石墨烯量子点中电子电子相互作用和自旋荷利分离的实验证据
Experimental evidence for electron-electron interaction and spin-charge separation in graphene quantum dots
论文作者
论文摘要
石墨烯量子点（GQD）可以表现出一系列壮观的现象，例如klein-tunneling诱导的Quasibound States1-6和浆果 - 相关的能量光谱7-15。根据先前的研究，所有这些有趣的量子现象似乎在自由电子图片1-15中都被充分理解。但是，GQD中的电子运动通过量子限制减少为量化轨道，这意味着动能可能与准粒子的库仑能相当，甚至比准库仑能相当，可能导致GQD中的外来相关相。在这里，我们提出了对石墨烯/WSE2异质结构设备中栅极可调GQD的扫描隧道显微镜和光谱研究，并首次报告了电子电子相互作用和相关性诱导的GQD中相关诱导的旋转带电分离。门控使我们能够精确地表征电子电子相互作用对GQD的能量光谱的影响。通过测量状态的密度与能量和位置的函数，我们明确发现了GQD中具有不同速度的两个密度波，这归因于实际空间中的自旋荷利分离。
Graphene quantum dots (GQDs) can exhibit a range of spectacular phenomena such as the Klein-tunneling-induced quasibound states1-6 and Berry-phase-tuned energy spectra7-15. According to previous studies, all these interesting quantum phenomena seem to be well understood in the free electron picture1-15. However, electronic motion in the GQDs is reduced to quantized orbits by quantum confinement, which implies that the kinetic energy may be comparable to or even smaller than the Coulomb energy of the quasiparticles, possibly resulting in exotic correlated phases in the GQDs. Here we present a scanning tunneling microscopy and spectroscopy study of gate-tunable GQDs in graphene/WSe2 heterostructure devices and report for the first time the observation of electron-electron interaction and correlation-induced spin-charge separation in the GQDs. Gating allows us to precise characterize effects of the electron-electron interaction on the energy spectra of the GQDs. By measuring density of states as a function of energy and position, we explicitly uncover two density waves with different velocities in the GQDs, attributing to spin-charge separation in real space.
