Molecular collapse in monolayer graphene

Abstract

Atomic collapse is a phenomenon inherent to relativistic quantum mechanics where electron states dive in the positron continuum for highly charged nuclei. This phenomenon was recently observed in graphene. Here we investigate a novel collapse phenomenon when multiple sub- and supercritical charges of equal strength are put close together as in a molecule. We construct a phase diagram which consists of three distinct regions: 1) subcritical, 2) frustrated atomic collapse, and 3) molecular collapse. We show that the single impurity atomic collapse resonances rearrange themselves to form molecular collapse resonances which exhibit a distinct quasi-bonding, anti-bonding and non-bonding character. Here we limit ourselves to a systems consisting of two and three charges. We show that by tuning the distance between the charges and their strength a high degree of control over the molecular collapse resonances can be achieved.

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Cited by in corpus (7)

• Relativistic Artificial Molecules Realized by Two Coupled Graphene Quantum Dots
• Molecular Collapse States in Elliptical Graphene/WSe2 Heterostructure Quantum Dots
• Confinement and edge effects on atomic collapse in graphene nanoribbons
• Graphene Dirac fermions in symmetric electric and magnetic fields: the case of an electric square well
• Molecular collapse in graphene: sublattice symmetry effect
• Massive and massless two-dimensional Dirac particles in electric quantum dots
• Analogue of atomic collapse for adatoms on rhombohedral multilayer graphene