Combing Magnetism with Superconductivity for Ultra-Fast Memory

The world is predicted to store over 180 zettabytes of data by 2025, a huge amount that would be equivalent to 38.3 trillion DVDs. Data is stored using magnets which is the best way to store data for long periods. However, lots of energy is wasted through heating which is inefficient and due to the current climate crisis, we must look for other solutions. As we shift towards more complex computation using quantum computers, which are much smarter than traditional computers which utilise the weird rules of quantum mechanics, this becomes a greater problem. Quantum computers operate at incredibly low temperatures and will require data storage which can also operate at this temperature. Superconductors are special materials that when cooled sufficiently, exhibit zero resistance meaning electric current flow very easily without any obstacles so no heat is generated. These materials could be used to solve this issue.

In recent studies, researchers have discovered that by combining magnets with superconductors in a unique sandwich-like structure, they can create a system where these materials can talk to each other. This interaction enables the transmission and manipulation of information, which can represent the binary 0s and 1s used in traditional computers. Magnets and superconductors talk but it is not known how and how fast which is important as we want ultrafast technology. To study the interactions between magnets and superconductors in the sandwich-like structures, we employ a cutting-edge technique called terahertz (THz). THz light, which falls between visible light and microwaves, operates on faster timescales than traditional electronics. THz spectroscopy allows us to take a ultrafast snapshot of what’s going on inside the material, helping us understand how magnets and superconductors talk to each other in sandwich-like structures at small timescales giving insights on what happens at the interface.

This project focuses on using THz spectroscopy to measure how fast different magnet superconductor sandwiches talk to each other. We want to see if we can use the superconductor to “write” information onto the magnet, like changing the direction of a compass. We give the superconductor a jolt which causes the superconductor to behave a bit like a magnet. Our goal is to see if the induced magnetic behaviour of the superconductor can be strong enough to flip the magnet’s direction next to it. If we can do this, it means we can control the magnet’s information using the superconductor’s power. We’re comparing our method to other ways of flipping magnets, like those used in commercial magnetic RAMs, to see if it’s faster and uses less energy.

Rhiannon Fletcher-Stones

NanoDTC PhD Student, c2023