SKM 2021 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 2: Quantum Chaos
DY 2.5: Vortrag
Dienstag, 28. September 2021, 11:30–11:45, H6
Dirac fermion optics and directed emission from single- and bilayer graphene cavities — •Jule Katharina Schrepfer1, Szu-Chao Chen2, Ming-Hao Liu2, Klaus Richter3, and Martina Hentschel4 — 1Technische Universität Ilmenau, 98693 Ilmenau, Germany — 2National Cheng Kung University, Tainan 70101, Taiwan — 3Universität Regensburg, 93040 Regensburg, Germany — 4Technische Universität Chemnitz, 09107 Chemnitz, Germany
High-mobility graphene hosting massless charge carriers with linear dispersion provides a promising platform for electron optics phenomena. Inspired by the physics of dielectric optical micro-cavities where the photon emission characteristics can be efficiently tuned via the cavity shape, we study corresponding mechanisms for trapped Dirac fermionic resonant states in deformed micro-disk graphene billiards and directed emission from those. In such graphene devices a back-gatevoltage provides an additional tunable parameter to mimic different effective refractive indices and thereby the corresponding Fresnel laws at the boundaries. Moreover, cavities based on single-layer and double-layer graphene exhibit Klein- and anti-Klein tunneling. Moreover,we find a variety of different emission characteristics depending on the position of the source where charge carriers are fed into the cavites. Combining quantum mechanical simulations with optical ray tracing and a corresponding phase-space analysis, we demonstrate strong confinement of the emitted charge carriers in the mid field of single-layer graphene systems and can relate this to a lensing effect. For bilayer graphene, trapping of the resonant states is more efficient.