Electron spins in slowly moving quantum dots may be controlled by electric fields

In the coming quantum computing era, information storage and processing may depend on so-called spintronic devices that exploit the electron spin as well as its charge as a unit of information. This will only be possible, however, if the spin of a single electron can be controlled. Researchers have recently suggested that it should be possible to control the spin of electrons in quantum dots with electric fields through spin-orbit coupling, which is the interaction of the electron's spin with its motion. It is this interplay between electric fields and electron spins that Prabhakar and Melnik have now modelled.

Spin-orbit coupling leads to a split in an electron's energy levels. which can be detected as line splitting in a spectrum. The researchers simulated this effect in quantum dots made from different semiconductor materials, moving slowly through electric fields. They solved the Schrodinger equation for the system, observed strong beating patterns in the spin values and revealed that spin-orbit coupling occurs in these slowly moving dots, inducing a magnetic field in the absence of an external one. These emerging magnetic properties suggest that the dots could, indeed, have potential in quantum computing as storage and processing devices.