Title
|
|
|
|
Electrical dipole on gapped graphene : bound states and atomic collapse
|
|
Author
|
|
|
|
|
|
Abstract
|
|
|
|
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 alpha 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 alpha. The anticrossings are more pronounced and move to higher charges Z alpha 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. |
|
|
Language
|
|
|
|
English
|
|
Source (journal)
|
|
|
|
Physical review B / American Physical Society. - New York, N.Y, 2016, currens
|
|
Publication
|
|
|
|
New York, N.Y
:
American Physical Society
,
2018
|
|
ISSN
|
|
|
|
2469-9969
[online]
2469-9950
[print]
|
|
DOI
|
|
|
|
10.1103/PHYSREVB.98.165420
|
|
Volume/pages
|
|
|
|
98
:16
(2018)
, 10 p.
|
|
Article Reference
|
|
|
|
165420
|
|
ISI
|
|
|
|
000447302700010
|
|
Medium
|
|
|
|
E-only publicatie
|
|
Full text (Publisher's DOI)
|
|
|
|
|
|
Full text (open access)
|
|
|
|
|
|