CONFERENCE SCOPE:
Advanced nanomaterials
INSTITUTION:
Institute Jean Lamour, Francia
TITLE:
Quantum materials for low-power electronics: spin-orbitronics with graphene-based interfaces and low-symmetry materials
ABSTRACT:
The interconversion of charge current into spin current due to spin-orbit coupling (SOC) play a crucial role in today’s spin-orbitronics [1]. In magnetic materials, Js transports electrons with spin polarization parallel to their magnetization. However, if they have strong spin-orbit coupling, Js with the orthogonal spin Hall effect symmetry also survives. We have shown that for GdFeCo [2]. In the first part of my talk, I will present results on a new heterostructure combining 2D materials such as graphene (Gr) and 3D materials such as Fe and Pt. Through spin pumping ferromagnetic resonance, we show a record efficiency for charge current production at room temperature in Fe/Gr/Pt. The experimental results are supported by first-principles calculations [3]. In the second part, I will present results with the van der Waals topological semimetal NbIrTe4, which has an orthorhombic crystallographic structure and a missing reflection plane. The bulk topological Weyl semimetal nature of NbIrTe4, characterized by its Weyl cone, significantly enhances the out-of-plane (OOP) spin Berry curvature, enabling an unprecedented OOP spin Hall conductivity exceeding 10^5 ℏ/2e⋅Ω-1m-1. This enhancement enables efficient and field-free spin-orbit torque switching of perpendicular magnetization with a low current density of 1.4 MA/cm2. The improved spin Hall conductivity reduces the overall power consumption by more than two orders of magnitude compared to existing systems, such as heavy metals [4]. Our findings pave a way for new experiments and technological applications.
Thanks to H2020-RISE ULTIMATE-I (ID 101007825), ERC CoG MAGNETALLIEN (ID 101086807) projects for financial support and to all collaborators [1-4].
[1] J.-C. Rojas-Sánchez and A. Fert, Phys Rev. Applied 11, 054049 (2019)
[2] D. Céspedes-Berrocal, et al. Advanced Materials 33, 2007047 (2021)
[3] A. Anadón, et al. Adv. Materials 37, 241854 (2025)
[4] W. Yang, et al. https://arxiv.org/abs/2504.05280 ]
BIO:
J. Carlos Rojas-Sánchez received his BSc from Universidad Nacional de Ingeniería (Lima, Peru) in 1999, and his MSc and PhD from Institute Balseiro (Bariloche, Argentina) in 2004 and 2011, respectively. After 4 years as a post-doc in Grenoble (CEA, Spintec and Neel Institute) and Palaiseau (UMPhi CNRS/Thales, now Albert Fert Laboratory), he achieved a permanent position as CNRS researcher in France. He is working at the Jean Lamour Institute in Nancy, France, since October 2015. He has also been the Head of IJL’s cleanroom facilities from 2018 to 2023. His main research interests span from spintronics to spin-caloritronics and spin-orbitronics. He is also the organizer of International Workshops in Spintronics held in Latin America such as Spin Peru 2019, Spin Argentina 2022 and Spin Galapagos 2025 in Ecuador. In 2020 he received the CNRS Bronze Medal award (for young researchers). He is the Principal Investigator of different projects in France and Europe such as H2020 MSCA RISE Ultimate-i. In 2023, he was awarded an ERC Consolidator grant for his MAGNETALLIEN project.