Creating and Probing Electron Whispering Gallery Modes in Graphene
arXiv:1505.02732 · doi:10.1126/science.aaa7469
Abstract
Designing high-finesse resonant cavities for electronic waves faces challenges due to short electron coherence lengths in solids. Previous approaches, e.g. the seminal nanometer-sized quantum corrals, depend on careful positioning of adatoms at clean surfaces. Here we demonstrate an entirely different approach, inspired by the peculiar acoustic phenomena in whispering galleries. Taking advantage of graphene's unique properties, namely gate-tunable light-like carriers, we create Whispering Gallery Mode (WGM) resonators defined by circular pn-junctions, induced by a scanning tunneling probe. We can tune the resonator size and the carrier concentration under the probe in a back-gated graphene device over a wide range, independently and in situ. The confined modes, revealed through characteristic resonances in the tunneling spectrum, originate from Klein scattering at pn junction boundaries. The WGM-type confinement and resonances are a new addition to the quantum electron-optics toolbox, paving the way to real-world electronic lenses and resonators.
References in corpus (14)
- Chiral tunneling and the Klein paradox in graphene
- Micrometer-scale ballistic transport in encapsulated graphene at room temperature
- Quantum interference and Klein tunneling in graphene heterojunctions
- Veselago Lens for Electrons: Focusing and Caustics in Graphene p-n Junctions
- Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
- Klein Backscattering and Fabry-Perot Interference in Graphene Heterojunctions
- Electron Beam Supercollimation in Graphene Superlattices
- Gate-controlled Guiding of Electrons in Graphene
- Electrostatic confinement of electrons in an integrable graphene quantum dot
- Caustics due to Negative Refractive Index in Circular Graphene p-n Junctions
- Fabry-Pérot interference in gapped bilayer graphene with broken anti-Klein tunneling
- Quantum and classical confinement of resonant states in a trilayer graphene Fabry-Perot interferometer
- High-pressure structural behaviour of HoVO4: Combined XRD experiments and ab initio calculations
- Rotational Excitation Spectroscopy with the STM through Molecular Resonances
Cited by in corpus (11)
- An On/Off Berry Phase Switch in Circular Graphene Resonators
- Electrostatically confined monolayer graphene quantum dots with orbital and valley splittings
- Tuning a Circular p-n Junction in Graphene from Quantum Confinement to Optical Guiding
- Stokes paradox in electronic Fermi liquids
- Generating nanoscale and atomically-sharp p-n junctions in graphene via monolayer-vacancy-island engineering of Cu surface
- Localization of massless Dirac particles via spatial modulations of the Fermi velocity
- Spatially resolving density-dependent screening around a single charged atom in graphene
- Chiral interface states in graphene - junctions
- Scanning tunneling microscopy and spectroscopy of nanoscale twisted bilayer graphene
- Nonlinear response of a ballistic graphene transistor with an ac-driven gate: high harmonic generation and THz detection
- Proximity-induced superconductivity in Landau-quantized graphene monolayers