Tue November 19, 2024 4:00 pm
CUA Seminar – Philip Kim: Anyon Braiding in Graphene Quantum Hall Interferometer
Location:Harvard Ory Forum (301 A/B) in the Goel Building (60 Oxford)
Philip Kim,
Harvard University
Ten Minute Talk:"Sensing Electron Spins of Copper Phthalocyanine via Relaxometry of Shallow NVs in Diamond" by
Boning Li,
MIT
The search for anyons, quasiparticles with fractional charge and exotic exchange statistics, has inspired decades of condensed matter research. Moreover, it has been predicted that exchange braiding of these particles, especially non-abelian anyons, can produce topologically protected logic operations that can serve as building blocks for fault-tolerant quantum computing. Fractional quantum Hall (FQH) effects, in which electrons are confined to two spatial dimensions and subjected to large magnetic fields, have long been predicted to host emergent fractionally charged excitations that obey neither fermionic nor bosonic exchange statistics. Quantum Hall (QH) interferometers allow direct observation of the anyon braiding phase via discrete interference phase jumps as the quasiparticle number changes. FQH Fabry-Pérot (FP) interferometers allow direct measurements of anyon entanglement via the entanglement phase (equivalently two exchanges) of quasiparticles around a confined cavity. By partially backscattering the current at two quantum point contact (QPC) constrictions, the conductance through the FP cavity includes interference terms depending on the phase accrued by quantum Hall (QH) edge-traveling quasiparticles. In this talk, we discuss the observation of the universal anyonic braiding phase in graphene-based quantum Hall interferometers. We demonstrate a new way to characterize the anyon exchange statistics using random telegraph noise that can be controlled by experimental parameters.