Observation of Giant Orbital Magnetic Moments and Paramagnetic Shift in Artificial Relativistic Atoms and Molecules
arXiv:2210.14256 · doi:10.1038/s41565-023-01327-0
Abstract
Massless Dirac fermions have been observed in various materials such as graphene and topological insulators in recent years, thus offering a solid-state platform to study relativistic quantum phenomena. Single quantum dots (QDs) and coupled QDs formed with massless Dirac fermions can be viewed as artificial relativistic atoms and molecules, respectively. Such structures offer a unique platform to study atomic and molecular physics in the ultra-relativistic regime. Here, we use a scanning tunneling microscope to create and probe single and coupled electrostatically defined graphene QDs to unravel the unique magnetic field responses of artificial relativistic nanostructures. Giant orbital Zeeman splitting and orbital magnetic moment are observed in single graphene QDs. While for coupled graphene QDs, Aharonov Bohm oscillations and strong Van Vleck paramagnetic shift are observed. Such properties of artificial relativistic atoms and molecules can be leveraged for novel magnetic field sensing modalities.
References in corpus (28)
- Two-Dimensional Gas of Massless Dirac Fermions in Graphene
- Quantum sensing
- Chiral tunneling and the Klein paradox in graphene
- Spins in few-electron quantum dots
- Interfacing single photons and single quantum dots with photonic nanostructures
- 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
- Colloquium: Artificial spin ice: Designing and imaging magnetic frustration
- A new transfer technique for high mobility graphene devices on commercially available hexagonal boron nitride
- Electron optics with ballistic graphene junctions
- Observing Atomic Collapse Resonances in Artificial Nuclei on Graphene
- Imaging electrostatically confined Dirac fermions in graphene quantum dots
- Creating and Probing Electron Whispering Gallery Modes in Graphene
- Mechanical cleaning of graphene
- 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
- Large tunable valley splitting in edge-free graphene quantum dots on boron nitride
- Creating and Steering Highly Directional Electron Beams in Graphene
- Tunable valley splitting and bipolar operation in graphene quantum dots
- Generating nanoscale and atomically-sharp p-n junctions in graphene via monolayer-vacancy-island engineering of Cu surface
- Berry phase jumps and giant nonreciprocity in Dirac quantum dots
- Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology
- Relativistic Artificial Molecules Realized by Two Coupled Graphene Quantum Dots
- Electrons imitating light: Frustrated supercritical collapse in charged arrays on graphene
- Control of Giant Topological Magnetic Moment and Valley Splitting in Trilayer Graphene
- Berry-phase switch in electrostatically-confined topological surface states