Abstract
Quantum Hall systems host highly correlated and degenerate electronic states, where exotic quasiparticles such as fractionalized anyons can emerge. However, conventional bulk measurements lack the spatial resolution to probe them individually. Using scanning tunneling spectroscopy (STS) on an ultraclean graphene device under a high magnetic field, we directly visualize quantum Hall quasiparticles in real space near single charged defects. The Coulomb potential of these defects lifts the Landau-level degeneracy, separating orbits with different angular momentum in energy and thereby enabling their individual imaging. When quasiparticles are bound to the impurity potential, distinct spectral features arise, encoding the number and type of bound states. By analyzing the spectral weight, we visualize localized quasiparticles in real space—realizing a quasiparticle microscope that reveals their distribution down to the single-defect limit and opens a pathway to observe and manipulate non-Abelian anyons.
*This work is supported by National Science Foundation through the CAREER program under Award No. DMR-2442363. J. D. acknowledges support from the New Frontier Grant, College of Arts & Sciences, Cornell University. D. P. and E. M. are supported by National Science Foundation Grant No. PHY-2409403. The device fabrication is performed in part in Cornell Center for Materials Research and in part at the Cornell NanoScale Facility, a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (Grant NNCI-2025233). K.W. and T.T. acknowledge support from the JSPS KAKENHI (Grant Numbers 21H05233 and 23H02052), the CREST (JPMJCR24A5), JST and World Premier International Research Center Initiative (WPI), MEXT, Japan.
