21 February 2019
Spinning faster, ultralow-power computational devices
Published online 28 August 2018
A bilayer film can store data by exploiting electron spin.
A bilayer film made of a magnetic material and a non-magnetic insulator displays remarkable potential to store data, a new study reveals.
The film can store data utilizing electron spin: a property that gives electrons an angular momentum and a tiny magnetic field.
Conventional silicon chips store data in binary digits (0s and 1s) using electrical charge and its movement. Like electrical charge, which has negative and positive values, spin has two states, up and down, and can be used to store data.
The bilayer film eliminates the movement of charge, so storage and computational devices made with it can run on ultralow power.
Jian-Ping Wang from the University of Minnesota in the US says, “This work has huge practical applications, as the film can be grown on a silicon substrate at room temperature employing a technique widely used in semiconductor industry.”
Researchers, including Aurelien Manchon from King Abdullah University of Science and Technology in Saudi Arabia, prepared the film by depositing a layer of a magnetic material on a bismuth selenide film grown on a silicon substrate.
The film converted externally applied current into spin that accumulated at the interface of the magnetic and bismuth selenide layers, explains Mahendra Dangi Chhetri from the University of Minnesota. The spin then transferred its spin-angular momentum to the magnetic layer, which can store data.
Next, the team plans to make new types of these films using different combinations of magnetic material and non-magnetic insulators, says Wang.
DC, M. et al. Room-temperature high spin–orbit torque due to quantum confinement in sputtered BixSe(1–x) films. Nat. Mater. https://doi.org/10.1038/s41563-018-0136-z (2018).