Magnonics in 2D materials

Oct 20, 2023 | Internships/PhD positions

 

Laboratoire: MPQ (Matériaux et Phénomènes Quantiques), Université Paris Cité & CNRS
Adress: Bâtiment Condorcet – 10 Rue A. Domon et L. Duquet – 75013 Paris
Internship/PhD supervisor: François Mallet
Tel: 0678692918
e-mail: francois.mallet@sorbonne-universite.fr

Scientific project:

Spintronics is a vast field of research, stimulated by its constantly evolving applications in information processing. One of the main challenges in spintronics is the efficient generation and detection of pure (charge-free) spin currents, paving the way for ultra-fast low-power devices. Understanding the importance of interface effects has led spintronics to focus on two-dimensional (2D) materials. Indeed, these materials can be combined with potentially defect-free interfaces. Moreover, they now cover all phases of condensed matter (metallic, semiconducting, insulating, superconducting and even recently magnetic) and present strong device potential due to their natural sensitivity to external parameters, such as proximity effect, electrostatic doping, and Moiré effects [1] for example.

In the TELEM team of the MPQ laboratory, a platform for injecting pure spin current i.e. magnons, into 2D materials by radiofrequency pumping of the resonance of an adjacent ferromagnetic metal has just been set up. In a recent work, we obtained a clear spin-pumping signature in graphene: the damping of the ferromagnetic resonance increases in its presence. The next stage of this project therefore aims to study not only the generation, but also the propagation of magnons in this material by inverse spin Hall effect in a material with strong spin-orbit coupling [2]. Conversely, we have also demonstrated that another 2D material such as WSe2 significantly enhances the coherence of Co’s thin-film FMR (on the order of a few nanometers). This opens up new prospects in the field of optomagnonics, with the possibility of making the coupling between magnons and photons tunable [3].

[1] J.F. Sierra, J. Fabian, R.K. Kawakami, et al., Nat. Nanotechnol. 16 (2021), 856–868
[2] D. Indolese, S. Zihlmann, P. Makk, et al., Phys. Rev. Applied 10 (2018), 044053.
[3] S. Yoshii, K. Kato, E. Shigematsu, et al. Phys. Rev. B 106, (2022) 174414.


Methods and techniques: micro and nanofabrication in clean-room environment (e-beam lithography, thin film deposition, …) structural characterizations by atomic force microscope, electrical transport and magnetotransport measurements from 1K to 350K, from DC to RF (10 GHz).
Possibility to go on with a PhD: YES
Envisaged fellowship: EDPIF

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