New quantum system could help design better spintronics

Researchers have created a new testing ground for quantum systems in which they can literally turn certain particle interactions on and off, potentially paving the way for advances in spintronics.

Spin transport electronics have the potential to revolutionize electronic devices as we know them, especially when it comes to computing. While standard electronics use an electron's charge to encode information, spintronic devices rely on another intrinsic property of the electron: its spin.

Spintronics could be faster and more reliable than conventional electronics, as spin can be changed quickly and these devices use less power. However, the field is young and there are many questions researchers need to solve to improve their control of spin information. One of the most complex questions plaguing the field is how the signal carried by particles with spin, known as spin current, decays over time.

"The signal we need to makespintronicswork, and to study these things, can decay. Just like we want good cell phone service to make a call, we want this signal to be strong," said Chuan-Hsun Li, a graduate student in electrical and computer engineering at Purdue University. "When spin current decays, we lose the signal."In the real world, electrons don't exist independently of everything around them and behave exactly how we expect them to. They interact with other particles and among different properties within themselves. The interaction between a particle's spin (an intrinsic property) and momentum (an extrinsic property) is known as spin-orbit coupling.

According to a new paper in Nature Communications, spin-orbit coupling and interactions with other particles can dramatically enhance spin current decay in a quantum fluid called Bose-Einstein condensate (BEC).