Researchers at UC Santa Barbara have potentially opened up a new avenue toward room temperature quantum information processing. By demonstrating the ability to image and control single isolated electron spins in diamond, they unexpectedly discovered a new channel for transferring information to other surrounding spins — an initial step towards spin-based information processing.
A team of researchers including graduate students Ryan Epstein and Felix Mendoza, and their advisor, David Awschalom, a professor of physics, were intrigued by the long-lived electronic spins of so-called nitrogen-vacancy impurities in the diamond crystal — defects that only consist of two atomic sites. So, about two years ago, they embarked on developing a sensitive room temperature microscope that would allow them to study individual defects through their light emission.
This microscope, with its unique precision in the control of the magnetic field alignment, has allowed them to not only detect individual nitrogen-vacancy defects, but also small numbers of previously invisible ‘dark’ spins from nitrogen defects in their vicinity. These spins are called ‘dark’ because they cannot be directly detected by light emission and yet, it appears that they may prove extremely useful.