EPFL Researchers Measure e/3 Charge in Graphene at 4/3, 5/3 and 7/3 Fillings
Updated
Updated · Quantum Zeitgeist · Aug 15
EPFL Researchers Measure e/3 Charge in Graphene at 4/3, 5/3 and 7/3 Fillings
3 articles · Updated · Quantum Zeitgeist · Aug 15
Summary
EPFL-led researchers directly measured e/3 fractional charge in bilayer graphene quantum Hall states, with clear signals at filling factors 4/3, 5/3 and 7/3.
A gate-defined antidot inside the graphene sheet isolated quasiparticle tunneling, letting the team infer charge from conductance oscillations instead of more complex interferometry.
The same device also found q = 2e/3 at 2/3, q = 3e/5 at 3/5, and mixed e/3 and 2e/3 signatures at 8/3, pointing to richer quasiparticle behavior there.
The bilayer-graphene structure uses graphite top, bottom and side gates with hexagonal boron nitride encapsulation, reducing bulk-edge interference that has complicated earlier graphene measurements.
Researchers say the antidot platform could be extended to other van der Waals materials, including systems pursued for fractional Chern insulators and non-Abelian quasiparticles.