| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:00 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2014 Meeting
Section: Solid State Physics and Materials Science
Title:
Graphene periodic multi-gated structures under magnetic field.
Authors:
A. ZUBAREV, Daniela DRAGOMAN
Affiliation:
Universitatea Bucuresti, Facultatea de Fizica
E-mail
alxzubarev@gmail.com
Keywords:
graphene, multibarrier structures, transfer matrix
Abstract:
One of the most interesting materials for nanotechnology is graphene. Graphene is very attractive for numerous applications for sensors, photovoltaics, and nanoelectronics because of its unusual electrical and optical properties. Graphene-based devices have high sensibility, small reaction time, low energy consumption and small dimensions. Because electrons in graphene cannot be modulated by electric fields in the case of normal incidence, their transmission can be modulated by magnetic fields or by electric fields at oblique incidence. A more efficient transmission modulation is obtained in periodic gated structures. In this research, we apply simultaneously electric and magnetic fields on a multibarrier structure in graphene consisting of several gated regions, on which the gate voltages can be modified independently. The electron transmission was analyzed using the total transfer matrix method. The transfer matrix for graphene in magnetic field was deduced using the Dirac equation and the condition of continuity for the spinorial wavefunction. As an example, we considered a multi-barrier structure with two gate electrodes on which different voltages are applied. By modifying the gate voltages, we can modulate the charge carrier transmission in the structure. In particular, the transmission depends on the Landau level in each region traversed by charge carriers. In practical applications, the current through the device is determined by the angular integral of the transmission coefficient. This parameter is also dependent on the various Landau levels in the graphene structure. The obtained results can be used in applications such as energetic filters for ballistic electrons or multiple-valued logic circuits.
|
|
|
|