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 (13)
- Chiral tunneling and the Klein paradox in graphene
- 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
- Creating and Probing Electron Whispering Gallery Modes in 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
- Creating and Steering Highly Directional Electron Beams in Graphene
- Generating nanoscale and atomically-sharp p-n junctions in graphene via monolayer-vacancy-island engineering of Cu surface
- Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology
- Control of Giant Topological Magnetic Moment and Valley Splitting in Trilayer Graphene
- Berry-phase switch in electrostatically-confined topological surface states