When matter is cooled and confined in two dimensions, electrons can enter exotic quantum states where they behave as if they carry only a fraction of the usual electron charge. These “anyons” — named for their unusual statistics — are the signature of topological order and are central to proposals for fault-tolerant quantum computing. Detecting them directly remains a major experimental challenge.
In this work, the authors show that light can help. In certain atomically thin semiconductor materials, electrons can pair with “holes” to form excitons — neutral quasiparticles that interact strongly with light. They predict that when an exciton is placed near a fractional Chern insulator, a material hosting anyons without the need for a magnetic field, it binds to a nearby anyon to form a new composite object: an exciton-anyon bound state. Using theoretical modeling and numerical simulations, they map out the conditions under which this binding occurs and estimate the energies involved.
The key result is that these bound states should be detectable in photoluminescence experiments — a standard optical technique — in realistic heterostructures built from twisted MoTe₂ and neighboring semiconductors. This opens a concrete route to directly imaging the fractional charges that are central to topological quantum matter using light.
Tianhong Lu and Luiz H. Santos,
Exciton-Anyon Binding in Fractional Chern Insulators: Spectral Fingerprints
Phys. Rev. Lett.136, 256605 (2026).
DOI: https://doi.org/10.1103/8bp8-g8g4
Research supported by the U.S. Department of Energy.