At my university, we weren’t required to take quantum mechanics. The whole premise behind it is that you can never truly “know” anything, just the probability of something right? It sounded a bit silly to me. Then I got into high-level electromagnetics and signal processing and had to deal with a lot more numbers that didn’t make sense. I’m glad some people decided to take that course because they are the ones making breakthroughs in quantum technology today. Some researchers recently published a paper detailing their discoveries in spin wave electronics or spintronics. Their revelations could pave the way for actual spintronics devices, like memory. This storage would come with several advantages, like non-volatility and ultra low power operation. These assets could make it the perfect choice for embedded applications like the Internet of Things (IoT) and would make it a serious competitor for flash memory.
Spin Wave Technology
Before we get into the recent breakthroughs we need to go over what spin wave technology actually is. Then we can talk about what exactly these researchers discovered.
Traditional electronics use electron charges to store information and perform operations. Transistors have on and off states that change when they pass electric currents. Spintronics also use electrons, but instead of using their charge characteristic they use their spin to store information. Electron spin has two states, which can be discerned by measuring the tiny magnetic fields they radiate. Researchers have been working out how to use these spin states to replace transistor based electronics.
A team at the National University of Singapore recently made some great progress on the spin wave front. Apparently one of the problems plaguing spin wave electronics is that wave signals are anisotropic, meaning they vary in different directions. The researchers, headed by Professor Adekunle Adeyeye, used a novel structure that allows them to propagate the same signal in multiple directions simultaneously. This configuration does not require an external magnetic field, which makes it easier to implement. Previously these same engineers discovered a way to transmit and manipulate spin wave signals without an external magnetic field. When combined, these two discoveries could bring us much closer to spintronic devices.
Electrons could be the next transistors.
Advantages of Spintronics
Just because something is new doesn’t necessarily mean it’s useful, so what does spin wave technology bring to the table? Spintronics has multiple advantages that could be put to good use in memory applications. They are ultra low power, non-volatile, and can use simple materials to store information.
Ultra Low Power - Transistors require a current in order to change their state. Spin states are easily flipped using much less energy and do not need a current to switch states.
Non-Volatile - One reason flash memory has become so popular is that it’s fast and non-volatile. That means it can store information without power. Spintronics don’t rely on a current or charge to maintain their position. Once an electron spin is up or down it stays that way until altered, making it non-volatile.
Common Materials - Though we may not think about materials often, many of the semiconductors used in electronics are quite specialized. Spin can be measured in materials like iron, copper, or aluminum. This could mean memory devices made out of common materials that are less expensive to source and incorporate into designs.
Though this article is focusing on storage, it’s worth mentioning that spin wave technology could also be useful for digital signal processing. The nature of spintronics gives it some computational advantages in processing signals and performing operations like Fourier Transforms.
The IoT will need low power memory for its scattered low power sensors.
Magnetic Memory Applications
Spin wave memory, also dubbed magnetic memory, already has multiple applications waiting for its technology to be realized. The market that needs it the most is the Internet of Things.
The IoT is on the cusp of explosive growth. Not only are our home appliances getting smart, so are cars, cities, and even our homes themselves. The IoT will see sensors scattered over huge areas and transmit information via a dedicated network for data collection and interpretation. These far flung sensors won’t be getting new batteries every year, so they need ultra low power memory to store the information they collect. That’s why so many companies are working to develop ultra low power flash. It will be the chosen storage solution for these networks.
Magnetic storage would be a great competitor for flash products. Companies have had to do years of research to get flash to ultra low power levels. Spin wave memory would start at that level, and could likely be improved. Spintronics also use more readily available materials, which could make them less expensive than conventional storage that uses specialized semiconductors.
The market is ready and waiting for spin wave technology. Breakthroughs like the ones made by these researchers in Singapore bring that tech one step closer. Soon spintronics won’t be some idea that we study in high-level quantum physics courses, they’ll be storing our eating habits in our smart forks.
Incorporating spintronics into your circuits won’t be an easy task. In order to do it well, you’ll need software that is used to integrating next generation design techniques, like Altium Designer. It has a plethora of PCB tools that can help you assimilate the technology of the future into your designs.
Have more questions about spintronics? Call an expert at Altium.