Improving the Efficiency of Spintronics by Replacing Magnetism With ElectricityApril 30, 2020 by Luke James
Electric currents drive our electronic devices, and the emerging “spintronics” field is looking to replace these currents with what are known as spin currents.
Essentially, spintronics is used to transfer information, much in the way that electric currents have always been used, but spintronics offers a range of benefits and advantages that researchers and scientists are only just beginning to understand.
Currently, the power efficiency of electronic devices is a limiting factor in technological development. This is because, in electric currents, electrons lose some energy as waste heat as they traverse the circuit.
The Role of Spintronics in Device Efficiency
Spintronics is said to improve upon this situation because instead of movement, it exploits the angular momentum of electrons to transfer information---their spin, a quantum property. Although electrons still move in spin currents, they move far less, and this dramatically improves efficiency.
In order to generate and detect spin currents, spintronics makes use of ferromagnetic materials. Unfortunately, magnetic switching of these materials uses a high amount of energy and this inhibits efficiency somewhat.
(Top) An example of the system developed. (Bottom) An experimental curve showing the evolution of charge produced as a function of the voltage applied to the ferroelectric material. Image credited to CNRS/Thales and Spintech (CNRS)/CEA/Université Grenoble Alpes)
Replacing Ferromagnetism with Ferroelectricity
Researchers at the Spintec Laboratory (CNRS/CEA/Université Grenoble Alpes) and the CNRS/Thales Laboratory recently presented a new approach that is reportedly able to detect spin information at low power by using a non-magnetic system. This research could pave the way for spintronic devices that are 1,000 times more efficient by operating on ferroelectricity rather than on ferromagnetism.
Above is an example of the system developed: A ferromagnetic material that can generate a spin current and inject it into an interface material where it is converted into a charge current.
Here, to change the sign of the charge current produced, polarisation of the ferroelectric material is reversed using an electric field. Traditionally, a magnetic field is required to do this.