Related Experiment Video
Updated: May 28, 2025
09:00
Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
9.8K
Photonic spin rings formed by toroidal spin momentum
Optics Letters
|February 14, 2025
Summary
Researchers demonstrate a novel 3D ring of transverse spin angular momentum (TSAM) in light, moving beyond linear constraints. This breakthrough in photonic spin offers new possibilities for energy and information transfer.
Area of Science:
- Optics and Photonics
- Light-Matter Interactions
Background:
- Transverse spin angular momentum (TSAM) of light, or photonic wheels, has significant applications.
- Current TSAM is limited to linear propagation directions.
Purpose of the Study:
- To demonstrate that TSAM can be oriented along a 3D ring structure.
- To explore new degrees of freedom in photonic spin manipulation.
Main Methods:
- Utilizing tightly focused circular polarization of light.
- Analyzing the phase difference between circular polarization and induced longitudinal polarization.
- Investigating the relationship between TSAM and the spatial curl of polarization orientation.
Main Results:
- Generated TSAM circulates in a ring due to a π/2 phase difference, creating azimuthal TSAM.
- TSAM was found to be closely related to the spatial curl of polarization orientation.
- Observed an array of photonic rings due to reversed spin directions every half wavelength.
Conclusions:
- A 3D spin ring of light's transverse angular momentum has been achieved.
- This new 3D spin ring structure adds a novel degree of freedom to photonic spin.
- The findings may lead to advancements in energy and information transfer methods.
More Related Videos
Related Concept Videos
01:03Atomic Nuclei: Nuclear Spin State Overview
848
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...
848
01:08Spin–Spin Coupling Constant: Overview
862
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...
862
01:08Atomic Nuclei: Nuclear Spin
1.6K
All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although protons and neutrons in nuclei may have higher half-integer spins owing to energetic factors.
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not...
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not...
1.6K
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
945
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
945
00:59Atomic Nuclei: Nuclear Magnetic Moment
1.0K
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
1.0K
01:27Toroids
2.8K
A toroid is a closely wound donut-shaped coil constructed using a single conducting wire. In general, it is assumed that a toriod consists of multiple circular loops perpendicular to its axis.
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb...
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb...
2.8K