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

Spin–Spin Coupling Constant: Overview01:08

Spin–Spin Coupling Constant: Overview

In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must have a...
Torque On A Current Loop In A Magnetic Field01:13

Torque On A Current Loop In A Magnetic Field

The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy.
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
Biot-Savart Law01:19

Biot-Savart Law

The Biot-Savart law gives the magnitude and direction of the magnetic field produced by a current. This empirical law was named in honor of two scientists, Jean-Baptiste Biot and Félix Savart, who investigated the interaction between a straight, current-carrying wire and a permanent magnet.
A current-carrying wire creates a magnetic field in its vicinity. Consider an infinitesimal current element dl in a wire. The direction of vector dl is along the direction of the current. The total magnetic...
Magnetic Force On A Current-Carrying Conductor01:25

Magnetic Force On A Current-Carrying Conductor

Moving charges experience a force in a magnetic field. Since the magnetic fields produced by moving charges are proportional to the current, a conductor carrying a current creates a magnetic field around it.
Consider a compass placed near a current-carrying wire. The wire experiences a force that aligns the needle of the compass tangentially around the wire. Thus, the current-carrying wire produces concentric circular loops of magnetic field. The magnetic field generated by a wire can be...
Magnetic Force Between Two Parallel Currents01:13

Magnetic Force Between Two Parallel Currents

Two long, straight, and parallel current-carrying conductors exert a force of equal magnitude on one another. The direction of the force depends on the current direction in the conductors.
The force exerted by the magnetic field due to the first conductor over a finite length of the second conductor is given as the product of the current in the second conductor and  the vector product of the length vector along the current element and the field due to the first conductor. According to the...

You might also read

Related Articles

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

Sort by
Same author

Application of acupuncture and moxibustion for keeping shape.

Journal of traditional Chinese medicine = Chung i tsa chih ying wen pan·1999
Same author

Two-effective-source method for the calculation of in-air output at various source-to-detector distances in wedged fields.

Medical physics·1999
Same author

Follow up of women with simple ovarian cysts detected by transvaginal sonography in the Tokyo metropolitan area.

British journal of obstetrics and gynaecology·1999
Same author

(R)-3,3,3-Trifluoro-2-hydroxy-2-methylpropionamides are orally active inhibitors of pyruvate dehydrogenase kinase.

Journal of medicinal chemistry·1999
Same author

Expression analysis of multidrug resistance associated genes in neuroblastomas.

Oncology reports·1999
Same author

A random survey of the Cryptosporidium parvum genome.

Infection and immunity·1999

Related Experiment Video

Updated: May 22, 2026

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
09:00

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Published on: June 28, 2018

The universal definition of spin current.

Z An1, F Q Liu, Y Lin

  • 1Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University , Wuhan 430072, China.

Scientific Reports
|May 8, 2012
PubMed
Summary
This summary is machine-generated.

This study defines spin, orbit, and total angular momentum currents in quantum electrodynamics. The research highlights the effective total angular momentum current as crucial for spintronics polarization and transport properties.

More Related Videos

Scanning SQUID Study of Vortex Manipulation by Local Contact
06:53

Scanning SQUID Study of Vortex Manipulation by Local Contact

Published on: February 1, 2017

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging
11:27

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging

Published on: April 4, 2013

Related Experiment Videos

Last Updated: May 22, 2026

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
09:00

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Published on: June 28, 2018

Scanning SQUID Study of Vortex Manipulation by Local Contact
06:53

Scanning SQUID Study of Vortex Manipulation by Local Contact

Published on: February 1, 2017

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging
11:27

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging

Published on: April 4, 2013

Area of Science:

  • Quantum electrodynamics
  • Condensed matter physics
  • Spintronics

Background:

  • Universal definitions for spin, orbit, and total angular momentum currents are established.
  • Conservation laws and continuity equations for these currents are explored.
  • Non-relativistic approximations are derived for physical interpretation and experimental analysis.

Purpose of the Study:

  • To define and analyze angular momentum currents within quantum electrodynamics.
  • To investigate the spin current in two-dimensional quantum spin-Hall systems.
  • To propose an improved descriptor for spintronic properties.

Main Methods:

  • Tensor formulation of angular momentum currents based on quantum electrodynamics.
  • Derivation of non-relativistic approximations.
  • Calculation of spin current for helical edge states in HgTe/CdTe quantum wells.
  • Deduction of a generalized spin-orbit coupling term.

Main Results:

  • Universal definitions and conservation properties of angular momentum currents are presented.
  • Spin current in HgTe/CdTe quantum wells demonstrates quantum spin-Hall system properties.
  • A generalized spin-orbit coupling term is derived for semiconducting media.

Conclusions:

  • The effective total angular momentum current is recommended over the pure spin current.
  • This effective current better describes polarization distribution and transport in spintronics.
  • The study provides a theoretical framework for understanding angular momentum transport in quantum systems.