Molecular Collapse States in Elliptical Graphene/WSe2 Heterostructure Quantum Dots

Abstract

In relativistic physics, both atomic collapse in heavy nucleus and Hawking radiation in black hole are predicted to occur through Klein tunneling process that couples particles and antiparticles. Recently, atomic collapse states (ACSs) were explicitly realized in graphene because of its relativistic Dirac excitation with large fine structure constant. However, essential role of the Klein tunneling on the ACSs remains elusive in experiment. Here we systematically study the quasibound states in elliptical graphene quantum dots (GQDs). Bonding and antibonding molecular collapse states formed by two coupled ACSs are observed in the elliptical GQDs. Our experiments, supported by theoretical calculations, indicate that the antibonding state of the ACSs will change into a Klein-tunneling-induced quasibound state, revealing deep connection between the ACSs and the Klein tunneling.

3 figures in main text

References in corpus (17)

• Chiral tunneling and the Klein paradox in graphene
• Quantum interference and Klein tunneling in graphene heterojunctions
• The Kernel Polynomial Method
• Friedel oscillations, impurity scattering and temperature dependence of resistivity in graphene
• The Coulomb impurity problem in graphene
• Klein Backscattering and Fabry-Perot Interference in Graphene Heterojunctions
• Vacuum Polarization and Screening of Supercritical Impurities in Graphene
• Atomic Collapse and Quasi-Rydberg States in Graphene
• Creating and Probing Electron Whispering Gallery Modes in Graphene
• An On/Off Berry Phase Switch in Circular Graphene Resonators
• Effect of a single impurity on the local density of states in monolayer and bilayer graphene
• Chebyshev-BdG: an efficient numerical approach to inhomogeneous superconductivity
• Tuning a Circular p-n Junction in Graphene from Quantum Confinement to Optical Guiding
• Role of pseudospin in quasiparticle interferences in epitaxial graphene probed by high-resolution scanning tunneling microscopy
• Generating nanoscale and atomically-sharp p-n junctions in graphene via monolayer-vacancy-island engineering of Cu surface
• Coexistence of electron whispering-gallery modes and atomic collapse states in graphene WSe2 heterostructure quantum dots
• Magnetic field dependence of the atomic collapse state in graphene

Cited by in corpus (4)

• Orbital hybridization in graphene-based artificial atoms
• Absence of edge states at armchair edges in inhomogeneously strained graphene under a pseudomagnetic field
• Atomic collapse of high-order singular potentials in graphene
• Probing Quantum Geometric Phases via Scanning Tunneling Microscopy