Researchers at MIT have successfully induced a durable magnetic state in an antiferromagnetic material using terahertz light. This discovery could revolutionize magnetic storage technologies by making them resistant to external disturbances, thereby improving the performance of memory and processors.
The MIT team used a terahertz laser to directly influence the atoms of an antiferromagnetic material. By precisely tuning the laser's oscillations to match the natural vibrations of the material's atoms, they were able to alter the alignment of atomic spins, creating a new magnetic state. This innovative method opens up prospects for controlling and switching antiferromagnetic materials, which are essential for future information processing technologies.
Unlike ferromagnetics, where the spins of atoms are aligned in the same direction, antiferromagnetics have alternating spins, which cancels out their overall magnetization. This characteristic makes antiferromagnetics insensitive to external magnetic fields but also difficult to manipulate. The use of terahertz light overcomes this limitation, offering a new way to control these materials.
The potential applications of this discovery are vast, particularly in the manufacturing of memory chips. Data could be stored in microscopic domains of the material, representing the '0' and '1' bits by specific spin configurations. This technology promises increased robustness against magnetic interference, reduced energy consumption, and improved storage density.
The material used in this study, FePS3, undergoes a transition to an antiferromagnetic phase at a critical temperature. By exciting the atomic vibrations of the material with terahertz light, the researchers were able to disrupt the spin alignment, inducing a new magnetic state. This transition persisted for several milliseconds after the laser was turned off, providing a time window to study the properties of this state.
This research paves the way for new techniques to manipulate quantum materials, with potential implications for information and communication technologies. The ability to induce and maintain magnetic states in antiferromagnetics could lead to significant advancements in data storage and information processing.
The work of the MIT team, published in
Nature, demonstrates the effectiveness of terahertz light in manipulating the magnetic properties of antiferromagnetic materials. This approach could be extended to other quantum materials, offering new perspectives for fundamental research and technological applications.
What is terahertz light?
Terahertz light lies in a part of the electromagnetic spectrum between microwaves and infrared. It is characterized by frequencies oscillating between 0.1 and 10 terahertz, corresponding to wavelengths ranging from 3 mm to 30 µm.
This light is particularly interesting for scientific research because it can interact with the atomic and molecular vibrations of materials. Unlike X-rays or ultraviolet light, terahertz light is non-ionizing, meaning it does not cause damage to biological or electronic materials.
Applications of terahertz light are vast, ranging from medical imaging to security, and including wireless communications. In the field of quantum materials, it offers a non-invasive method to manipulate electronic and magnetic properties at the atomic scale.
Why are antiferromagnetics difficult to manipulate?
Antiferromagnetic materials are composed of atoms with alternating spins, meaning they point in opposite directions. This configuration cancels out the overall magnetization of the material, making it insensitive to external magnetic fields.
This insensitivity is both an advantage and a disadvantage. On one hand, it makes antiferromagnetics robust against magnetic disturbances, which is ideal for applications requiring high stability. On the other hand, it makes these materials difficult to control and manipulate, limiting their use in current technologies.
The MIT discovery, using terahertz light to induce a magnetic state in an antiferromagnetic material, opens new possibilities for overcoming these limitations. By precisely adjusting the frequency of the light to match the atomic vibrations of the material, the researchers were able to disrupt the spin alignment, creating a new magnetic state.