Spin-Orbit Torques in van der Waals Heterostructures

Spin-orbit torques (SOTs) in 2D material stacks offer a route to ultralow-power magnetic memory and logic[1]. We will design, build, and understand van der Waals (vdW) heterostructures that combine topological insulators (TI), transition-metal dichalcogenides, graphene, and 2D magnets (e.g., Fe₃GeTe₂) to generate and control SOTs. Taking advantage of atomically sharp interfaces, symmetry, and twist angle, we will tailor interfacial spin-orbit coupling and disentangle spin, orbital (including orbital Hall), and proximity effects (spin-orbit and exchange), which alter the band structure of the 2D materials and drive efficient torque and field-free switching. Recent demonstrations of robust SOT switching in fully vdW TI/FM stacks [2] and the broad outlook for 2D-material-enabled MRAM motivate this work (see for example our recent Perspective [1]). The selected PhD student will learn to i) fabricate vdW stacks via exfoliation/MBE and deterministic transfer ii) pattern nanodevices, iii) quantify damping-like and field-like torques using second-harmonic Hall and optical Kerr microscopy, iv) tune symmetry with gating and stacking order to realize deterministic, field-free switching and v) identify the dominant charge to spin conversion channels. The project advances fundamental understanding of interfacial spin-charge-orbital conversion and design rules for maximizing SOT efficiency, positioning the candidate at the forefront of quantum-materials-enabled spintronics.

[1] H. Yang, S. O. Valenzuela et al., Nature 606, 663 (2022).
[2] T. Guillet et al., Nano Lett.24, 822 (2024)

Education: A Master (or Licenciatura) degree in Physics, Material Science, Nanotechnology or related discipline is required at the time of joining ICN2.

Knowledge, professional experience and competences: Applicants must show motivation, excellent disposition towards challenging research problems and a good level of the English language. A strong background on solid-state physics and experience in experimental methods will be valued, including: i) Nanoscience and Nanotechnology, ii) Electronic transport, and ii) Nanofabrication techniques

The Physics and Engineering of Nanodevices Group focuses on the development of novel devices specifically designed to gain insight into physical properties of materials at the nanoscale, combining state of the art lithographic and chemical methods with magnetic and electrical transport characterisation.
The Group’s research is currently centred on spintronic devices in metals, graphene and topological insulators, including thermoelectric effects. Spintronics introduces the spin degree of freedom into device design and has been predicted to enable a revolutionary class of electronics with functionalities exceeding current semiconductor technology. Conventional electronic devices are based on charge carriers and their associated energy, which limits their speed due to energy dissipation. Spintronics, which is based on spin orientation and spin coupling, promises much higher speeds, low power demands, non-volatility and higher integration densities.