Related Experiment Video
Updated: Aug 5, 2026
08:48
Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms
Published on: September 25, 2020
Generation and Enhancement of Persistent Nanoscale Magnetization in All-Dielectric Metasurfaces by Optically Injected
Shivaksh Rawat1, Samyobrata Mukherjee1, Gennady Shvets1
1School of Applied and Engineering Physics, Cornell University, Ithaca, New York, USA.
Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
|August 3, 2026
Summary
Time-varying dielectric metasurfaces create temporal interfaces for metasurface-guided waves (MGWs), enabling frequency conversion and localized magnetic fields. This research demonstrates a novel method for manipulating light propagation in time using engineered materials.
Area of Science:
- Optics and Photonics
- Materials Science
- Electromagnetism
Background:
- Dielectric metasurfaces offer unique optical resonance properties.
- Metasurface-guided waves (MGWs) enable novel light-matter interactions.
- Time-varying optical elements are crucial for advanced photonic applications.
Purpose of the Study:
- To investigate the use of time-varying dielectric metasurfaces as temporal interfaces.
- To demonstrate frequency conversion and temporal scattering of MGWs.
- To explore the generation of localized quasistatic magnetic fields.
Main Methods:
- Analytical modeling of time-varying metasurface resonances.
- Electromagnetic simulations to analyze field distributions.
- Generation of free carriers to induce temporal changes.
Main Results:
- Demonstrated frequency conversion and temporal scattering of infrared MGWs.
- Achieved generation of large, localized quasistatic magnetic fields.
- Observed persistent nanoscale magnetization supported by residual currents.
Conclusions:
- Time-varying metasurfaces act as effective temporal interfaces for MGWs.
- The generated magnetic fields and magnetization have potential applications in nanoscale devices.
- Energy partitioning during temporal scattering is characterized.
Related Concept Videos
01:31Ferromagnetism
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...
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...
01:26Diamagnetism
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
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...
01:22Carrier Generation and Recombination
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...