(Springer Nature, 2021-02-25) Ronen, Yuval; Werkmeister, Thomas; Najafabadi, Danial; Pierce, Andrew; Anderson, Laurel; Shin, Young Jae; Lee, Si Young; Lee, Young Hee; Johnson, Bobae; Watanabe, Kenji; Taniguchi, Takashi; Yacoby, Amir; Kim, Philip
Interferometers probe the wave-nature and exchange statistics of indistinguishable particles, for example electrons in the chiral one-dimensional edge channels of the quantum Hall effect (QHE). Quantum point contacts can split and recombine these channels, enabling interference of charged particles. Such quantum Hall interferometers (QHIs) can unveil the exchange statistics of anyonic quasiparticles in the fractional quantum Hall effect (FQHE). Here, we present a fabrication technique for QHIs in van der Waals (vdW) materials and realize a tunable, graphene-based Fabry-Pérot (FP) QHI. The graphite encapsulated architecture allows observation of FQHE at 3T magnetic field and precise partitioning of integer and fractional edge modes. We measure pure Aharonov-Bohm interference in the integer QHE, a major technical challenge in small FP interferometers, and find that edge modes exhibit high visibility interference due to large velocities. Our results establish vdW heterostructures as a versatile alternative to GaAs-based interferometers for future experiments targeting anyonic quasiparticles.
