Unprecedented spin properties revealed in new artificial materials

In collaboration with researchers from Charles University in Prague and the CFM Center (CSIC-UPV/EHU) in San Sebastian, the Nanodevices group of the CIC nanoGUNE has designed a new complex material with emerging properties in the field of spintronics. This discovery, published in the journal Natural materialsopens up a range of new possibilities for the development of new, more efficient and more advanced electronic devices, such as those that integrate magnetic memories into processors.

The discovery of two-dimensional materials with unique characteristics has led to a surge in research on these materials, because new effects are produced when two layers of these materials are stacked to form a heterostructure. It has recently been observed that tiny rotations of these layers can significantly change the properties of this heterostructure.

“In this work, we studied the stacking of two layers of graphene and tungsten selenide (WSe₂)”, explains Ikerbasque research professor Félix Casanova, co-leader of the Nanodevices group at nanoGUNE and who led this work. “If the two layers are placed on top of each other and rotated at a precise angle, a spin current is generated in a specific desired direction,” added Casanova.

Spin (one of the properties of electrons and other particles) is normally transferred in a direction perpendicular to the electric current. Managing these spin currents is one of the main limitations of spintronics, electronics that use spin to store, manage and transfer information. However, “this work shows that this limitation actually disappears when appropriate materials are used,” Casanova said.

“By simply stacking two layers and applying a ‘magic’ twist, we can obtain new spin-related properties that do not exist in the initial materials. The more flexibility we have in choosing materials, the greater the possibilities for designing next-generation devices.”