Related Experiment Video
Updated: May 9, 2026
14:52
Fabrication of Three-Dimensional Graphene-Based Polyhedrons via Origami-Like Self-Folding
Published on: September 23, 2018
Strong magnetophotoelectric effect in folded graphene
Friedemann Queisser1, Ralf Schützhold
1Fakultät für Physik, Universität Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany.
Physical Review Letters
|August 13, 2013
Summary
Researchers explored electronic transport in folded graphene under a magnetic field. They discovered robust modes enabling efficient charge separation via photon excitation, leading to strong magnetophotoelectric effects even at room temperature.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Graphene exhibits unique electronic properties.
- Magnetic fields can alter charge carrier behavior.
- Folded graphene structures offer novel possibilities for electronic devices.
Purpose of the Study:
- Investigate electronic transport in graphene subjected to a specific transversal magnetic field.
- Identify robust modes and their properties.
- Explore potential applications in charge separation and energy conversion.
Main Methods:
- Solving the effective Dirac equation for graphene in a spatially varying magnetic field.
- Analyzing the resulting electronic modes and energy gaps.
- Theoretical modeling of magnetophotoelectric and magnetothermoelectric effects.
Main Results:
- Discovery of robust propagating modes along the graphene fold.
- These modes exhibit a finite energy gap.
- Particles and holes move in opposite directions within these modes.
- Photon excitation leads to nearly perfect charge separation.
Conclusions:
- The studied system demonstrates a strong magnetophotoelectric effect.
- A significant magnetothermoelectric effect is also predicted.
- These effects are robust and observable even at room temperature.
- Folded graphene in magnetic fields presents a promising platform for novel electronic and energy applications.
Related Concept Videos
02:26Photoelectric Effect
When light of a particular wavelength strikes a metal surface, electrons are emitted. This is called the photoelectric effect. The minimum frequency of light that can cause such emission of electrons is called the threshold frequency, which is specific to the metal. Light with a frequency lower than the threshold frequency, even if it is of high intensity, cannot initiate the emission of electrons. However, when the frequency is higher than the threshold value, the number of electrons ejected...
01:27Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:24Potential Due to a Magnetized Object
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
The vector...
01:27π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...
01:15Magnetic Vector Potential
In electrostatics, the electric field can be written as the negative gradient of the potential. In magnetostatics, the zero divergence of the magnetic field ensures that the magnetic field can be expressed as the curl of a vector potential. This potential is known as the magnetic vector potential.
Consider an ideal solenoid with n turns per unit length and radius R. If I is the current through the solenoid, the magnetic field inside the solenoid is expressed as the product of vacuum...
Consider an ideal solenoid with n turns per unit length and radius R. If I is the current through the solenoid, the magnetic field inside the solenoid is expressed as the product of vacuum...
01:30Paramagnetism
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...