Yang Fangyuan, Zibrov Alexander A, Bai Ruiheng, Taniguchi Takashi, Watanabe Kenji, Zaletel Michael P, Young Andrea F
Department of Physics, University of California, Santa Barbara, California 93106, USA.
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
Phys Rev Lett. 2021 Apr 16;126(15):156802. doi: 10.1103/PhysRevLett.126.156802.
We describe an experimental technique to measure the chemical potential μ in atomically thin layered materials with high sensitivity and in the static limit. We apply the technique to a high quality graphene monolayer to map out the evolution of μ with carrier density throughout the N=0 and N=1 Landau levels at high magnetic field. By integrating μ over filling factor ν, we obtain the ground state energy per particle, which can be directly compared to numerical calculations. In the N=0 Landau level, our data show exceptional agreement with numerical calculations over the whole Landau level without adjustable parameters as long as the screening of the Coulomb interaction by the filled Landau levels is accounted for. In the N=1 Landau level, a comparison between experimental and numerical data suggests the importance of valley anisotropic interactions and reveals a possible presence of valley-textured electron solids near odd filling.
我们描述了一种实验技术，用于在静态极限下以高灵敏度测量原子级薄层材料中的化学势μ。我们将该技术应用于高质量的石墨烯单层，以绘制出在高磁场下μ随载流子密度在整个N = 0和N = 1朗道能级上的演化。通过对填充因子ν积分μ，我们获得了每个粒子的基态能量，该能量可直接与数值计算进行比较。在N = 0朗道能级中，我们的数据表明，只要考虑填充的朗道能级对库仑相互作用的屏蔽，在整个朗道能级上无需可调参数即可与数值计算达成异常一致。在N = 1朗道能级中，实验数据与数值数据之间的比较表明了谷各向异性相互作用的重要性，并揭示了在奇数填充附近可能存在谷纹理电子固体。
