Experimental Determination of the Energy per Particle in Partially Filled Landau Levels

We describe an experimental technique to measure the chemical potential ? in atomically thin layered materials with high sensitivity and static limit. apply a quality graphene monolayer map out evolution of carrier density throughout N=0 N=1 Landau levels at magnetic field. By integrating over filling factor ?, we obtain ground state energy per particle, which can be directly compared numerical calculations. In level, our data show exceptional agreement calculations whole level without adjustable parameters as long screening Coulomb interaction by filled is accounted for. comparison between suggests importance valley anisotropic interactions reveals possible presence valley-textured electron solids near odd filling.Received 13 August 2020Accepted 15 February 2021DOI:https://doi.org/10.1103/PhysRevLett.126.156802© 2021 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFractional quantum Hall effectInteger effectPhysical SystemsGrapheneTwo-dimensional systemCondensed Matter & Materials Physics