Despite more than two decades of research, the microscopic origins of several key physical mechanisms, such as the interfacial Dzyaloshinskii-Moriya interaction (DMI) [1], perpendicular magnetic anisotropy (PMA) [2], spin-charge conversion [3-4], and spin-orbit torques [5], occurring in thin film or at interfaces, remain largely elusive, despite their central importance to modern spintronics, even in the prototypical Pt|Co|light-element system.This talk will be divided into two parts, highlighting the rich physics associated with orbital angular momentum, both at equilibrium and out of equilibrium.
In the first part, I will show how the careful engineering of magnetic multilayers, through the optimization of both their bulk and interfacial properties, enables the stabilization of various topological spin textures, such as magnetic skyrmions [6] and cocoons [7-8], at room temperature. I will then demonstrate how these textures can be driven by spin–orbit torques and electrically detected. Beyond their fundamental scientific interest, I will also present our recent results demonstrating their potential for neuromorphic computing through proof-of-concept devices [9].
In the second part, I will discuss how electric-field-induced orbital angular momentum (OAM) at interfaces between light elements provides a new mechanism for generating additional spin–orbit torque (SOT) contributions, offering a promising alternative to conventional heavy-metal-based approaches in spintronics [10]. As an example, I will show that measure a large damping-like torque together with a giant field-like torques by second harmonic techniques [5], once again unexpected at such metallic interfaces, that we attribute a large interfacial Rashba interaction of orbital origin [11]. Finally, I will present recent theoretical and numerical results showing how the interplay between transverse spin textures in 3d films and engineered conductivity gradients can open up new pathways for generating efficient spin–orbit torques, with potentially significant implications for the development of future non-volatile electronic devices [3-4].
Acknewledgements : W. Bouckaert, J. Chiliquinga, M. Samy, E. Quadrati, Y. Sassi, N. Sebe, B. Bony, W. Legrand, K. Ray, Y. Xu, A. Pezo, S. Krishnia, S. Mallick, T. Da Camara, M. Chsiev, J. Li, T. Valet, S. Collin, J.M. George, J. Grollier, A. Fert, N. Reyren and H. Jaffrès
Funding : acknlowledge the support from a France 2030 government grant managed by the French National Research Agency PEPR SPIN ANR-22-EXSP 0002 (CHIREX), ANR-22-EXSP 0007 (SPINMAT), ANR-22-EXSP 0009 (SPINTHEORY), ANR-22-PEPR-Electronique-EMCOM. We also ackowledge the EU with EIC Pathfinder OPEN grant 101129641 “OBELIX” and Marie Skłodowska-Curie Actions - Doctoral Network (MSCA-DN) 101226840 “ORBIS”
References : [1] F. Ajejas, VC et al, Phys. Rev. Mat. 6, L071401 (2022) ; [2] S. Krishnia, VC et al, Phys. Rev. Appl. 24, 024055 (2025) ; [3] T. Valet, VC et al, Phys. Rev. Lett. 135, 256301 (2025) ; [4] T. Valet, VC et al, arXiv:2610.18800v1 (2026) ; [5] S. Krishnia, VC et al, Nano Letters, 23, 6785 (2024) ; [6] A. Fert, N. Reyren and V. Cros, Nat. Rev. Mat. 2, 17031 (2017) ; [6] M. Grellier, VC et al,, Nature Communications 13, 6843 (2022) ; [7] J. J. Chiliquinga-Jacome, VC et al., Phys. Rev. B 113, 174435 (2026) ; [9] T. Da Camara Santa Clara Gomes, VC et al, Nature Electronics 1, 11 (2025) ; [10] K.J. Lee, V. Cros, H.W. Lee, Nature Materials 23, 1302 (2024) ; [11] S. Nikolaev, VC et al, Nano Letters 24, 13465 (2024).
