Researchers from Linköping University suggested a new device concept capable of efficiently transferring the information carried by electron spin to light at room temperature
In a research published in Nature Communications on September 03, 2018, a team of researchers from Linköping University and the Royal Institute of Technology in Sweden, suggested a new device concept that can transfer the information carried by electron spin to light at room temperature. An electron spins around its own axis. The clockwise rotation is referred to as spin-up and counterclockwise rotation is referred to as spin-down. These two states in spintronics represent the binary bits of 0 and 1. In principle, a light-emitting device can convert the information encoded by these spin states into light that can carry the information over a long distance through optic fibers. Such transfer of quantum information facilitates a technology known as ‘opto-spintronics.’
The spin state of the electron determines the properties of the emitted light, thereby defining the information transfer in opto-spintronics. In chiral light, the electric field rotates either clockwise or counter-clockwise when seen in the direction of travel of the light. The direction of spin of the electron determine the rotation of the electric field. However, electrons easily lose their spin orientations when the temperature rises.
Now, in a study led by Weimin Chen at the Department of Physics, Chemistry and Biology, IFM, at Linköping University, researchers devised an efficient spin-light interface. The device consists small disks of gallium nitrogen arsenide (GaNAs). The height of the disks is around two nanometres and these are stacked on top of each other. A thin layer of GaAs is placed between the disks to form chimney-shaped nanopillars. The researchers introduced minimal defects into the material that led to unique ability of the proposed device to enhance spin signals. Less than one out of a million gallium atoms are displaced from their designated lattice sites in the material. The resulting defects act as efficient spin filters capable of draining electrons with an unwanted spin orientation and preserving the ones with the desired spin orientation.