Spin capacitor cuts heats and power

In what is claimed to be a world first, physicists have developed a so-called spin capacitor that could herald new electronics that require less power and generate less heat.

spin capacitor
A sample of the advanced material being prepared for muon spin spectroscopy (Image: Leeds University)

The advance by scientists at Leeds University generates and holds the spin state of electrons for a number of hours compared to previous efforts that held the spin state for a fraction of a second. Their results are published in Science Advances.

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A conventional capacitor holds energy in the form of electric charge and the development from Leeds does this also whilst storing the spin state of a group of electrons. According to the university, this could lead to a storage device measuring one square inch that could store 100 Terabytes of data.

In a statement, research supervisor Dr Oscar Cespedes, Associate Professor in the School of Physics and Astronomy, said: "This is a small but significant breakthrough in what could become a revolution in electronics driven by exploitation of the principles of quantum technology.

"At the moment, up to 70 per cent of the energy used in an electronic device such as a computer or mobile phone is lost as heat, and that is the energy that comes from electrons moving through the device's circuitry. It results in huge inefficiencies and limits the capabilities and sustainability of current technologies. The carbon footprint of the internet is already similar to that of air travel and increases year on year.

"With quantum effects that use light and eco-friendly elements, there could be no heat loss. It means the performance of current technologies can continue to develop in a more efficient and sustainable way that requires much less power."

Dr Matthew Rogers, one of the lead authors, commented: "Our research shows that the devices of the future may not have to rely on magnetic hard disks. Instead, they will have spin capacitors that are operated by light, which would make them very fast, or by an electrical field, which would make them extremely energy efficient.

"This is an exciting breakthrough. The application of quantum physics to electronics will result in new and novel devices."

How it works

In conventional computing, information is coded and stored as a series of bits made up of ones and zeros on a hard disk. Those zeroes and ones can be represented or stored on the hard disc by changes in the polarity of magnetised regions on the disc.

With quantum technology, spin capacitors could write and read information coded into the spin state of electrons by using light or electric fields.

The research team developed the spin capacitor by using a materials interface made from buckminsterfullerene (buckyballs), manganese oxide and a cobalt magnetic electrode. The interface between the nanocarbon and the oxide is able to trap the spin state of electrons.

The time it takes for the spin state to decay has been extended by using the interaction between the carbon atoms in the buckyballs and the metal oxide in the presence of a magnetic electrode.

The scientists believe the advances they have made can be built on, most notably towards devices that are able to hold spin state for longer periods of time.