Harnessing Orbital Angular Momentum for Novel Orbital Electronics
Main applicant: Peter Oppeneer, Division of Materials Theory, Uppsala University
Fellow applicants: Mahmoud Abdel-Hafiez and Venkata Kamalakar Mutta, X-ray Photon Science, Jan Rusz, Materials Theory, Uppsala University and Johan Åkerman, University of Gothenburg
Grant amount: SEK 36 100 000 SEK during five years
Financier: Project grant from the Knut and Alice Wallenberg Foundation
Existing technologies for processing digital data are reaching their limits in terms of energy efficiency and growth capacity due to parasitic effects that arise when devices are made smaller and manipulated with currents at a faster rate. Sustaining the growth rate for both storage and processing of information requires the harnessing of novel physical mechanisms able to overcome existing limitations and lift technology to a next higher level.
Spin currents, generated by charge-to-spin conversion through spin-orbit coupling in heavy metals, have become employed recently in spin-based devices. However, apart from spin, electrons also carry orbital angular momentum, a quantity that so far has not come into the picture as information carrier.
The goal of this research program is to establish novel pathways to harness orbital polarization and orbital currents to actively control the magnetization state in prototypical devices. Our main objective is to demonstrate that orbital information can be generated, transported and exploited in a similar manner as spin information, but has decisive advantages for future applications in terms of materials’ requirements, since huge orbital effects can be generated without strong spin-orbit coupling.
The latter feature makes orbital currents highly attractive for the development of future low-power functional components that operate at room temperature and are made of superior light and cheap ‘green’ metals and oxides and free of environmentally harmful heavy metals.
To address our scientific objective, we have formed a synergistic theory-experiment research team that gathers frontier competence in materials theory, detection of magnetic currents, nanoscale magnetism, single-crystal preparation and fabrication of spin-orbit torque devices. These competences combined will empower a platform to exhaustively investigate orbital information transport and to chart a route for its future utilization in orbital-based electronics.