High spatial resolution charge sensing of quantum Hall states

Abstract

Charge distribution offers a unique fingerprint of important properties of electronic systems, including dielectric response, charge ordering and charge fractionalization. We develop a new architecture for charge sensing in two-dimensional electronic systems in a strong magnetic field. We probe local change of the chemical potential in a proximitized detector layer using scanning tunneling microscopy (STS), allowing us to infer the chemical potential and the charge profile in the sample. Our technique has both high energy (<0.3 meV) and spatial (<10 nm) resolution exceeding that of previous studies by an order of magnitude. We apply our technique to study the chemical potential of quantum Hall liquids in monolayer graphene under high magnetic fields and their responses to charge impurities. The chemical potential measurement provides a local probe of the thermodynamic gap of quantum Hall ferromagnets and fractional quantum Hall states. The screening charge profile reveals spatially oscillatory response of the quantum Hall liquids to charge impurities, and is consistent with the composite Fermi liquid picture close to the half-filling. Our technique also paves the way to map moiré potentials, probe Wigner crystals, and investigate fractional charges in quantum Hall and Chern insulators.

References in corpus (13)

• Boron nitride substrates for high-quality graphene electronics
• Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
• Fractional Chern insulators in magic-angle twisted bilayer graphene
• Integer and fractional Chern insulators in twisted bilayer MoTe2
• Visualizing Broken Symmetry and Topological Defects in a Quantum Hall Ferromagnet
• Anomalous Hall Crystals in Rhombohedral Multilayer Graphene I: Interaction-Driven Chern Bands and Fractional Quantum Hall States at Zero Magnetic Field
• Direct observation of a magnetic field-induced Wigner crystal
• Correlated Hofstadter Spectrum and Flavor Phase Diagram in Magic Angle Graphene
• Energy gap of the even-denominator fractional quantum Hall state in bilayer graphene
• Hofstadter states and reentrant charge order in a semiconductor moiré lattice
• Precise Experimental Test of the Luttinger Theorem and Particle-Hole Symmetry for a Strongly Correlated Fermionic System
• High spatial resolution charge sensing of quantum Hall states
• Local imaging of high mobility two-dimensional electron systems with virtual scanning tunneling microscopy

Cited by in corpus (6)

• High spatial resolution charge sensing of quantum Hall states
• Molecular anyons in fractional quantum Hall effect
• Imaging the Sub-Moiré Potential Landscape using an Atomic Single Electron Transistor
• Sensing the binding and unbinding of anyons at impurities
• Quantization and quantum oscillations of the sublattice charge order in Dirac insulators
• Manipulating Charge Distribution in Moiré Superlattices by Light