Next-Generation Electronics

For decades, researchers have been studying the quantum property of electron spin as a possible way to improve the storage, transfer and processing of information. Known as spintronics, the field is widely seen as a key step in the development of quantum computing.

Spintronics is based on the fact that, in addition to their fundamental negative electrical charge, electrons rotate on their own axis, giving them a magnetic moment (i.e., magnetic strength and orientation). In metals, this property has been studied for the possibility of storing large amounts of data. But a recent breakthrough in the use of spintronics in semiconductors is the possibility of converting spin-based quantum information into light – a field known as opto-spintronics – which would greatly enhance processing and transmission speeds.

One problem with past attempts at developing semi-conductor spintronic devices has been the inability to orient and maintain the same spin state in all of the electrons at room temperature and above. They tend to randomize at higher temperatures, so the best that was previously achieved was 60 percent. But a team of researchers recently reported success rates of up to 90 percent at temperatures as high as 110 degrees Celsius (230 degrees Fahrenheit).

They created a structure consisting of layers of different semiconductor materials, which serves to polarize the electrons so that they are all oriented with the same spin. As each electron encounters nanoscale regions of quantum dots (10,000 times smaller than a human hair), it emits a single photon of light, the angular momentum of which is dependent on the direction of spin. The advancement could someday become a common platform for uniting light-based and spin-based quantum technologies.