Related Experiment Video
Updated: Oct 11, 2025
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.3K
PT-Symmetry-Enabled Spin Circular Photogalvanic Effect in Antiferromagnetic Insulators
Ruixiang Fei1, Wenshen Song1, Lauren Pusey-Nazzaro1
1Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130, USA.
Physical Review Letters
|December 3, 2021
Summary
We discovered a new way to generate highly spin-polarized currents at room temperature in antiferromagnetic insulators using the spin circular photogalvanic effect (spin CPGE). This breakthrough could enable ultrafast spintronics applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Ultrafast spintronics relies on short timescale spin dynamics in antiferromagnets.
- Generating highly spin-polarized currents at room temperature in antiferromagnets is a significant challenge.
Purpose of the Study:
- To propose and demonstrate a novel mechanism for generating highly spin-polarized currents at room temperature in antiferromagnetic insulators.
- To explore the spin circular photogalvanic effect (spin CPGE) for ultrafast spintronics.
Main Methods:
- First-principles simulations were employed to demonstrate the spin CPGE.
- The study focused on bilayer CrI3 and room-temperature antiferromagnetic hematite.
Main Results:
- The spin CPGE was shown to produce highly spin-polarized currents at room temperature in parity-time (PT)-symmetric antiferromagnetic insulators.
- The magnitude of the spin photocurrent was found to be comparable to charge photocurrents in ferroelectric materials.
- The generated spin photocurrent is insensitive to spin-orbit interactions.
Conclusions:
- The spin CPGE offers a promising route for realizing fast-dynamic and temperature-robust pure spin currents.
- This effect is applicable to a wide range of PT-symmetric antiferromagnetic materials, including topological axion insulators.
- The findings challenge the conventional understanding of spin current generation mechanisms.
Related Concept Videos
01:14π 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
01:03Atomic Nuclei: Nuclear Spin State Overview
1.2K
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...
1.2K
01:31Ferromagnetism
2.5K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.5K
03:02Colors and Magnetism
12.5K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.5K
01:27π Electron Effects on Chemical Shift: Overview
1.2K
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,...
1.2K
01:08Spin–Spin Coupling Constant: Overview
1.1K
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...
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...
1.1K