Antiferromagnetic tunneling junction. High-resolution transmission electron microscopy image of the antiferromagnetic junction showing layers of different materials (left). Diagram showing the materials’ magnetic properties (right).
Credit: Nakatsuji et al. CC-BY
A class of nonvolatile memory devices, called MRAM, based on quantum magnetic materials, can offer a thousandfold performance beyond current state-of-the-art memory devices. The materials known as antiferromagnets were previously demonstrated to store stable memory states, but were difficult to read from. This new study paves an efficient way for reading the memory states, with the potential to do so incredibly quickly too.
You can probably blink about four times a second. You could say this frequency of blinking is 4 hertz (cycles per second). Imagine trying to blink 1 billion times a second, or at 1 gigahertz; it would be physically impossible for a human. But this is the current order of magnitude in which contemporary high-end digital devices, such as magnetic memory, switch their states as operations are performed. And many people wish to push the boundary a thousand times further, into the regime of a trillion times a second, or terahertz.
The barrier for realizing faster memory devices may be the materials used. Current high-speed MRAM chips, which aren’t yet so common as to appear in your home computer, make use of typical magnetic, or ferromagnetic, materials. These are read using a technique called tunneling magnetoresistance. This requires the magnetic constituents of ferromagnetic material to be lined up in parallel arrangements. However, this arrangement creates a strong magnetic field which limits the speed at which the memory can be read from or written to.
“We’ve made an experimental breakthrough that surpasses this limitation, and it’s thanks to a different kind of material, antiferromagnets,” said Professor Satoru Nakatsuji from the University of Tokyo’s Department of Physics. “Antiferromagnets differ from typical magnets in many ways, but in particular, we can arrange them in ways other than parallel lines. This means we can negate the magnetic field that would result from parallel arrangements. It’s thought that the magnetization of ferromagnets is necessary for tunneling magnetoresistance to read from memory. Strikingly, however, we found it’s also possible for a special class of antiferromagnets without magnetization, and hopefully it can perform at very high speeds.”
Nakatsuji and his team think that switching speeds in the terahertz range is achievable, and that this is possible at room temperature too, whereas previous attempts required much colder temperatures and did not yield such promising results. Though, to improve upon its idea, the team needs to refine its devices, and improving the way it fabricates them is key.
“Although the atomic constituents of our materials are fairly familiar — manganese, magnesium, tin, oxygen, and so on — the way in which we combine them to form a useable memory component is novel and unfamiliar,” said researcher Xianzhe Chen. “We grow crystals in a vacuum, in incredibly fine layers using two processes called molecular beam epitaxy and magnetron sputtering. The higher the vacuum, the purer the samples we can grow. It’s an extremely challenging procedure and if we improve it, we will make our lives easier and produce more effective devices too.”
These antiferromagnetic memory devices exploit a quantum phenomenon known as entanglement, or interaction at a distance. But despite this, this research is not directly related to the increasingly famous field of quantum computing. However, researchers suggest that developments such as this might be useful or even essential to build a bridge between the current paradigm of electronic computing and the emerging field of quantum computers.
Original Article: Approaching the terahertz regime
More from: University of Tokyo
The Latest Updates from Bing News
Go deeper with Bing News on:
Antiferromagnetic memory devices
- Revolutionizing Memory Tech: The Rise of Low-Power Multiferroic Nanodots
Tokyo Institute of Technology researchers have developed BFCO nanodots for efficient and non-destructive memory technology, promising advancements in low-power magnetic memory devices. Traditional mem ...
- This electrode material allows 33x more energy storage in wearables
Fiber-like electrodes with exceptional strength, lightness, and flexibility, promises improved energy storage in wearable devices.
- Turbocharged Skyrmions: Accelerating Toward the Future of Computing
Scientists discovered that skyrmions, potential future bits for computer memory, can now move at speeds up to 900 m/s, a significant increase facilitated by the use of antiferromagnetic materials. An ...
- Skyrmions move at record speeds: a step towards the computing of the future
Anticipated as future bits in computer memory, these nanobubbles offer enhanced avenues for information processing in electronic devices ... thanks to the use of an antiferromagnetic material ...
- Skyrmions move at record speeds: A step towards the computing of the future
An international research team led by scientists from the CNRS has discovered that the magnetic nanobubbles known as skyrmions can be moved by electrical currents, attaining record speeds up to 900 ...
Go deeper with Bing News on:
Nantiferromagnets
- Newfound ‘altermagnets’ shatter the magnetic status quo
The newly discovered type of magnetic material could improve existing tech, including making better and faster hard drives.
- Turbocharged Skyrmions: Accelerating Toward the Future of Computing
Scientists discovered that skyrmions, potential future bits for computer memory, can now move at speeds up to 900 m/s, a significant increase facilitated by the use of antiferromagnetic materials. An ...
- Spintronics Using Altermagnets and Antiferromagnets
Here, compensated magnets, like altermagnets and antiferromagnets, have the advantage — they cannot easily be affected by external magnetic fields, but often only by spin-currents using spintronics.
- Using ultrasound to probe antiferromagnets
But another class of magnetic materials known as antiferromagnets, in which the magnetic fields of adjacent atoms point in opposite directions, offers several advantages over ferromagnets. In ...
- Using ultrasound to probe antiferromagnets
Figure 1: Two plots showing the results of using ultrasound to probe a magnetic material known as an antiferromagnet at temperatures of 4.2 kelvin (left) and 10 ...