Scientists at ICN2 Describe Theoretically New Interactions that Occur in Low-Dimensional Materials

by Jose M Arcos

These important findings could help improve the performance of novel technologies such as magnetic memories.

Researchers in the Theoretical and Computational Nanoscience Group at ICN2, headed by ICREA Prof. Stephan Roche, have theoretically described new types of interactions that occur in so-called Dirac materials (such as graphene and other two-dimensional materials), aiming towards the development of magnetic memories technology. This research is related to the European Research Council (ERC) grant awarded to Dr José H. García, Senior Researcher in the group. The results have recently been published in the journal Physical Review Letters.

Within the elementary cell of a magnetic memory, we find a magnetic material coupled to a conducting material. The objective is to control the orientation of the magnetization, up-wards or down-wards, by passing an electric current through the conductor. By these means a force is applied on the magnetization rotating its direction, in a phenomenon which is known as spin-orbit torque.

According to this publication, unique torque components appear in Dirac materials that do not occur in conventional metals and have been overlooked until now, due to a special coupling between the spin and pseudospin angular momenta of Dirac materials. This mechanism may lead to a performance enhancement by incorporating these novel materials in developing technologies.

This article represents an advance in one of the main research areas of this group: the study of spin dynamics and entanglement properties in Dirac materials and van der Waals heterostructures, aiming to pioneer new methods for quantum information manipulation.

Reference article:

Medina Dueñas, J., García, J.H., Roche, S. (2024). Emerging Spin-Orbit Torques in Low-Dimensional Dirac Materials. Physical Review Letters. https://doi.org/10.1103/PhysRevLett.132.266301