2018/10/15 by R. Van Pottelberge, B. Van Duppen, F. M. Peeters · 12 citations
Materials Science · Physics and Astronomy · #Atomic physics #Bound state #Condensed matter physics #Dipole #Graphene research and applications #Physics #Quantum and electron transport phenomena #Quantum mechanics #Surface and Thin Film Phenomena #Wave function #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.98.165420
published in Physical review. B./Physical review. B 98(16) (American Physical Society)
openalex publication_date 2018/10/15 · arxiv created 2018/10/19 · arxiv updated 2018/10/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the energy spectrum, wave functions, and local density of states of an electrical dipole placed on a sheet of gapped graphene as function of the charge strength Z\ensuremathα for different sizes of the dipole and for different regularization parameters. The dipole is modeled as consisting of a positive and negative charge. Bound states are found within the gap region with some energy levels that anticross and others that cross as function of the impurity strength Z\ensuremathα. The anticrossings are more pronounced and move to higher charges Z\ensuremathα when the length of the dipole decreases. These energy levels turn into atomic collapse states when they enter the positive (or negative) energy continuum. A smooth transition from the single-impurity behavior to the dipole one is observed: The states diving towards the continuum in the single-impurity case are gradually replaced by a series of anticrossings that represent a continuation of the diving states in the single-impurity case. By studying the local density of states at the edge of the dipole we show how the series of anticrossings persist in the positive and negative continuum.