Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

1.4K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.4K
Carrier Transport01:21

Carrier Transport

629
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
629
Magnetic Field Of A Current Loop01:16

Magnetic Field Of A Current Loop

5.1K
Consider a circular loop with a radius a, that carries a current I. The magnetic field due to the current at an arbitrary point P along the axis of the loop can be calculated using the Biot-Savart law.
5.1K
Biasing of Metal-Semiconductor Junctions01:27

Biasing of Metal-Semiconductor Junctions

361
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
361
Force On A Current Loop In A Magnetic Field01:17

Force On A Current Loop In A Magnetic Field

3.5K
Magnetic forces on wires carrying current are most frequently applied in motors. A DC motor is a device that converts electrical energy into mechanical work. In motors, wire loops are enclosed in a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate. The direction of the current is reversed once the loop's surface area is lined up with the magnetic field, causing a constant torque on the loop. During the process,...
3.5K
MOSFET: Enhancement Mode01:22

MOSFET: Enhancement Mode

518
Enhancement-mode MOSFETs are pivotal components in electronics, distinguished by their capacity to act as highly efficient switches. They are part of the larger family of metal-oxide Semiconductor Field-Effect Transistors (MOSFETs). They are available in two types: p-channel and n-channel, each tailored to specific polarity operations.
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
518

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Layer-selective hydrogenation and proton transport in twisted bilayer graphene.

Nature communications·2026
Same author

Symmetry analysis of the mono- and bilayer Lieb-Kagome lattices.

Journal of physics. Condensed matter : an Institute of Physics journal·2026
Same author

Tunable anisotropic electronic transport in bilayer phosphorene Y-junctions.

Nanotechnology·2025
Same author

Nonlocal electrodynamics of two-dimensional anisotropic magnetoplasmons.

Nanophotonics (Berlin, Germany)·2025
Same author

Electronic properties of multilayered Lieb, transition, and Kagome lattices.

Nanotechnology·2025
Same author

Ultra-confined plasmons reveal moiré patterns in a twisted bilayer graphene-talc heterostructure.

Nanoscale·2025

Related Experiment Video

Updated: Oct 9, 2025

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
10:36

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Published on: January 21, 2016

10.7K

Modulation of persistent current in graphene quantum rings.

F R V Araújo1,2, D R da Costa2, A J C Chaves3

  • 1Instituto Federal do Piauí-Campus São Raimundo Nonato, 64670-000, São Raimundo Nonato, PI, Brazil.

Journal of Physics. Condensed Matter : an Institute of Physics Journal
|December 21, 2021
PubMed
Summary

Long-range impurity potentials in graphene quantum rings affect persistent currents. Controlling p-n-p junction voltage modulates these currents, offering tunable electronic properties in graphene devices.

Keywords:
grapheneimpurity potentialpersistent currentpnp junctionquantum rings

More Related Videos

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

9.8K
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
11:42

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Published on: July 24, 2015

15.6K

Related Experiment Videos

Last Updated: Oct 9, 2025

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
10:36

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Published on: January 21, 2016

10.7K
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

9.8K
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
11:42

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Published on: July 24, 2015

15.6K

Area of Science:

  • Condensed Matter Physics
  • Materials Science
  • Quantum Mechanics

Background:

  • Graphene quantum rings exhibit unique electronic properties due to their 2D structure and massless charge carriers.
  • Persistent currents in such systems are sensitive to potential variations and magnetic fields.

Purpose of the Study:

  • To investigate the impact of long-range impurity potentials on persistent currents in graphene quantum rings.
  • To model the effects of non-uniform potentials and explore localized states.
  • To demonstrate voltage-controlled modulation of persistent currents via p-n-p junctions.

Main Methods:

  • Modeling impurity potentials as finite regions within the graphene ring.
  • Utilizing a theoretical approach that accounts for graphene's relativistic charge carriers.
  • Analyzing the energy spectrum and persistent current modifications.

Main Results:

  • Non-uniform impurity potentials can be modeled by adding a phase shift to the charge carrier wave function.
  • Localized electronic states are found to exist within the impurity regions.
  • Persistent current in graphene quantum rings is tunable by adjusting the voltage of a p-n-p junction.

Conclusions:

  • Long-range impurity potentials significantly influence persistent currents in graphene quantum rings.
  • The p-n-p junction offers a viable mechanism for controlling and tuning persistent currents.
  • This research provides insights into the design of novel graphene-based electronic devices.