Efficient Valves for Electron Spins

(University of Basel, August 06, 2020)

Researchers at the University of Basel, in collaboration with colleagues from Pisa, recently developed a new concept that uses the electron spin to switch an electrical current. To achieve this, the scientists formed two small semiconductor islands (quantum dots) behind each other on a nanowire and generated magnetic fields in the quantum dots using nanomagnets. Using an external field, they were subsequently able to control these magnets individually and thus could determine whether a quantum dot allowed electrons to pass with a spin directed upward (up) or downward (down) with far greater efficiency than in conventional spin valves. In addition to fundamental research, the concept could also prove useful in the quest to use electron spins as the smallest information unit (quantum bit) in a quantum computer.