High frequency magnetic resonance could revolutionize electronics, A team of physicists has found an electrical method to detect Terrachertz electromagnetic waves which are very difficult to detect.
This discovery can help miniature microchip devices and increase sensitivity.
Terahertz is a unit of frequency of electromagnetic waves: one gigahertz is equivalent to 1 billion Hertz; 1 terahertz is equivalent to 1000 gigahertz. Detection of High frequency magnetic resonance could revolutionize electronics.
The higher the frequency, the faster the information is sent. Mobile phones, for example, work with several gigahertz. on the phenomenon of magnetic resonance in antiferromagnetic materials. Such materials, also called antiferromagnets, offer unique advantages for applications with nanoscale devices based on ultra-fast and rotating applications.
The researchers produced spin currents in antiferromagnets, an important physical variable in spintronics, and killed them with electricity.
To achieve this, they use terahertz radiation to pump magnetic resonance in chromium and to facilitate its detection of High frequency magnetic resonance could revolutionize electronics.
In ferromagnets such as magnets, electrons spin up or down in the same direction, thus ensuring the collective strength of the material.
In the case of antiferromagnets, the arrangement of atoms is such that electronic rotation is canceled, with half of the rotation pointing up or down in the direction opposite to the other half.
Electrons have innate angular momentum which assesses the way in which the spinning top presses around the vertical axis.
When the electron precession frequency coincides with the frequency of electromagnetic waves generated by an external electron source, magnetic resonance occurs and manifests itself as a highly amplified signal that is more easily detected.
To create such magnetic resonance, a team of physicists at UC Riverside and UC Santa Barbara work with 0.24 terahertz radiation, which is produced in terahertz science and technology facilities on the Santa Barbara campus. This is exactly the same as the frequency of electron precession in chrome.
Subsequent magnetic resonance imaging produces a spin current, which the researchers convert to direct current.
“We were able to show that electrical voltage can be generated by antiferromagnetic resonance, a spintron effect that has never been done experimentally before.
Shi, director of the energy-funded research and development center for nanoscale electronic systems or SHINES at UC Riverside, said that the discovery of post-terahertz and terahertz radiation was a challenge.
Today’s communication technology uses gigahertz microwaves.
However, for greater bandwidth, people tend to use terahertz microwaves, according to researchers.
The generation of terahertz microwaves is not difficult, but it is our job to detect it.
Antiferromagnets are statically unattractive, dynamic but interesting.
The precession of stopping electrons in antiferromagnets is much faster than ferromagnets, which leads to frequencies two to three times higher than ferromagnetic frequencies, which allows faster information transmission. According to the researchers, the rotational dynamics of antiferromagnets take place in much shorter time intervals than with ferromagnets, which offers attractive advantages for possible applications for ultra-fast components.
Antiferromagnets are everywhere and more common than ferromagnets.
Many ferromagnets such as iron and cobalt become antiferromagnetic when oxidized. Many antiferromagnets are good insulators with low power dissipation. Researchers have discussed rotational sensitivity by focusing on platinum and tantalum as metal detectors.
If the chromium signal comes from spin, platinum and tantalum register the signal with the opposite polarity.
However, if the signal is caused by heat, both metals register the signal with the same polarity. This is the first successful generation and detection of pure spin currents in antiferromagnetic materials, which is a hot topic in spintronics.