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 bonding, anti-bonding and non-bonding character. Here we limit ourselves to 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.
- Publication:
-
2D Materials
- Pub Date:
- October 2019
- DOI:
- 10.1088/2053-1583/ab3feb
- arXiv:
- arXiv:1909.00558
- Bibcode:
- 2019TDM.....6d5047V
- Keywords:
-
- atomic collapse;
- graphene;
- electronic structure;
- molecular collapse;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- doi:10.1088/2053-1583/ab3feb