Periodic Reporting for period 1 - OBELIX (Orbital Engineering for Innovative Electronics)
Berichtszeitraum: 2024-04-01 bis 2025-03-31
Microelectronics development has long prioritized performance over sustainability. However, alternatives to traditional semiconductor technology have emerged—most notably spintronics, which uses electron spin instead of charge to process information. Spintronics enabled magnetic read-heads, various sensors, and more recently, non-volatile memories now entering the market, including in Europe. A decade ago, the field shifted toward spin-orbitronics, which leverages materials with strong spin-orbit coupling to enhance device performance, enabling ultrafast, high-density memories. Yet, this promising technology depends heavily on scarce, critical raw materials such as Pt, Ir, Ta, and Bi.
We propose to change the game by developing an entirely new technology based on abundant metals (such as Cu or Al), reinforcing sustainable and resilient advanced microelectronics. This innovative technology is rooted in recently discovered (partly by the consortium) physical mechanisms that exploit the electron’s orbital angular momentum (OAM), rather than its spin. Orbitronics, as we name it, could lead to new families of electronic components, from memories to sensors and logic, and possibly THz emitters and rf nano-oscillators without the need for heavy metals. It has the potential not only to outperform existing devices but also to be strategically resilient and environmentally responsible. We propose a focused program to design and characterize new heterostructures with maximized current- and optically-driven OAM enabling entirely novel orbitronic devices made of abundant metals with low environmental footprint.
The four objectives of OBELIX are:
1. Demonstrate the successful implementation of orbital currents in original devices relevant to information technology, including an orbital torque memory outperforming SOT-MRAM, an electrically controlled orbital switch for programmable logic and a vortex-beam controlled THz emitter.
2. Reveal efficient orbital transport in light metal heterostructures by identifying promising materials for orbital-to-charge conversion using theoretical and numerical modeling, demonstrate long-range orbital transport and large interconversion rates, developing novel experimental techniques enabling the electrical and optical probe of orbital currents.
3. A systematic characterization of orbital transport parameters (orbital conductivity and relaxation length, orbital-charge conversion rate, orbital polarizability…) in a wide range of materials (light metals, oxide interfaces, 2D materials...) to establish optimal materials.
4. Contribute to the public awareness concerning critical materials in microelectronics
Theoretical models addressing various aspects of orbital transport have been published, including models of orbital pumping, orbital diffusion, and orbital Hall and Edelstein effects in realistic systems. These works have been published in high-profile journals, including Physical Review Letters, and pave the way to predictive simulation of orbital transport.
A number of experimental results have also been published, demonstrating several key features of orbitronics: (i) long-range torque in PtCo magnets (Nature Physics 2024), (ii) a large non-reciprocity between orbital-to-charge and charge-to-orbital interconversion (Nano Letters 2025), (iii) the surprisingly large orbital Rashba-Edelstein effect at Al/Co interfaces (Nano Letters 2024), (vi) a very large orbital torque in Ni/Si (unpublished) and Ni/V (unpublished), (v) orbital pumping in Nb/Ni and Al/Co bilayers (unpublished).
During the first reporting period, the consortium published 20 papers in peered-reviewed journals on all aspects of orbitronics covered by the work program. Some of these papers were published in high-profile journals (Physical Review Letters, Nature Physics, Nature Communications, Nano Letters) and received major attention from the community. Among these results, reported in the Continuous Reporting and described in detail above, we emphasize the first systematic study of orbitronics-assisted magnetic memory by the JGU partner, which constitutes a major milestone towards the project’s central objective. The consortium members were, overall, invited to deliver presentations about research results obtained in the frame of OBELIX in 27 conferences and workshops worldwide.
On the experimental side, we emphasize two main results standing beyond the state of the art: (i) the discovery of very large orbital-charge conversion in Si, Nb and at Al surfaces and, most importantly for the technical success of OBELIX, (ii) the subtantial reduction of critical current and power consumption in a magnetic memory by using light metals as orbital sources. The latter achievement is an important milestone of the project and was obtained much earlier than initially scheduled.