2014/06/30 by Anastasia Varlet, Ming‐Hao Liu, Ming-Hao Liu +10 · 106 citations
Materials Science · Physics and Astronomy · #Bilayer graphene #Condensed matter physics #Electron #Geometric phase #Graphene #Graphene research and applications #Materials science #Nanotechnology #Optoelectronics #Physics #Quantum and electron transport phenomena #Quantum mechanics #Quantum tunnelling #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.113.116601
published in Physical Review Letters 113(11), 116601 (American Physical Society) · 5 pages, 4 figures
openalex publication_date 2014/09/08 · arxiv created 2014/09/30 · arxiv updated 2014/10/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report the experimental observation of Fabry-Pérot interference in the conductance of a gate-defined cavity in a dual-gated bilayer graphene device. The high quality of the bilayer graphene flake, combined with the device's electrical robustness provided by the encapsulation between two hexagonal boron nitride layers, allows us to observe ballistic phase-coherent transport through a 1-μm-long cavity. We confirm the origin of the observed interference pattern by comparing to tight-binding calculations accounting for the gate-tunable band gap. The good agreement between experiment and theory, free of tuning parameters, further verifies that a gap opens in our device. The gap is shown to destroy the perfect reflection for electrons traversing the barrier with normal incidence (anti-Klein tunneling). The broken anti-Klein tunneling implies that the Berry phase, which is found to vary with the gate voltages, is always involved in the Fabry-Pérot oscillations regardless of the magnetic field, in sharp contrast with single-layer graphene.