Description du sujet de thèse

The SPINCHIP project explores an emerging frontier in terahertz (THz) science, developing hybrid photonic-spintronic integrated circuits for chip-scale THz generation. Terahertz technology is a critical enabler for next-generation breakthroughs in wireless communication (6G and beyond), high-speed computing, advanced sensing, or even precision metrology and fundamental solid-state physics studies. However, today's methods for generating and processing THz signals — using conventional electronic and free-space photonic approaches — are bulky, inefficient, limited in frequency range and otherwise difficultly tunable and controllable. This bottleneck holds back major technological innovations.
This project takes a novel approach by leveraging spintronics, which exploits the intrinsic spin of electrons in thin ferromagnetic layers to convert optical femtosecond pulses into ultrabroadband THz radiation. Such inverse spin Hall spintronic THz emitters (ISHE STE) have opened a whole new paradigm for efficient and tunable THz generation due to their ultrafast response, magnetic field control and quasi-independence on pumping wavelength. The integration of ISHE STE's in compact photonic circuit feeding platform is expected to greatly expand the functionality of this innovative THz generation technology. By integrating these emitters into a silicon nitride photonic platform, we aim to develop compact, highly tunable, and efficient sources of pulsed and continuous-wave THz radiation (100 GHz–10 THz) that can be integrated into future high-speed technologies — paving the way for miniaturized, scalable, and power-efficient THz systems. The French-Swiss consortium partners have already initiated first preliminary steps towards such a novel integrated hybrid spin-photonic THz emitter. The PhD candidate will be part of this cutting-edge research initiative under the guidance of two top-level research institutions with access to state-of-the-art experimental and technological facilities.
This exciting new direction of hybrid integrated spin-photonic circuitry is largely unexplored, leaving many challenges unresolved. A few of the exciting scientific questions, the PhD student will tackle are the following:
• Optimizing Spintronic Terahertz Emission at the Chip Scale: traditional spintronic THz emitters have demonstrated remarkable broadband performance, but their integration into compact photonic circuits remains largely unexplored.
• Efficient optical pumping & waveguiding: while bulk spintronic emitters rely on free-space optical pumping, integrating them with silicon nitride waveguides introduces new challenges in optical coupling, dispersion, and nonlinear interactions.
• THz extraction & on-chip signal processing: unlike conventional free-space THz emitters, integrated spintronic devices must efficiently route generated THz signals using chip-scale antennas and transmission lines.
• Continuous-wave Terahertz synthesis & miniaturization: conventional THz generation techniques rely on bulky optical frequency combs and free-space photomixing. The translation to on-chip equivalents are tantalizing.

Contexte de travail

The activity takes place within the THz Photonics group of the Institute of Electronics, Microelectronics, and Nanotechnology (IEMN, https://www.iemn.fr/) located in close proximity to the University of Lille campus. This PhD will be carried out as part of the Franco-Swiss international ANR project SPINCHIP (in partnership with EPFL in Lausanne). The PhD candidate will work closely with the Swiss team.
The selected PhD candidate will actively contribute to:
• Understanding the physics of integrated spintronic emitters, including optimal layer thicknesses, generation efficiency, and noise characteristics.
• Designing and fabricating hybrid photonic-spintronic chips, leveraging state-of-the-art nanofabrication techniques at EPFL and IEMN.
• Developing advanced THz signal extraction and processing techniques, including broadband antennas and impedance-matched transmission lines.
• Demonstrating continuous-wave THz generation using stabilized optical frequency combs.
• Building specialized THz metrology setups for on-chip characterization and benchmarking of novel THz sources.

Candidate Profile
We are seeking an exceptionally motivated and talented candidate with a strong background in one or more of the following areas:
• Photonics & Integrated Optics (waveguide design, nonlinear optics, Kerr combs, etc.)
• Spintronics & Magnetism (thin films, ultrafast spin dynamics, spin-Hall effect)
• THz Science & Metrology (generation, detection, spectroscopy)
• Nanofabrication & Microelectronics (cleanroom processing, lithography, sputtering deposition)
Applicants should hold an MSc degree (or equivalent) in physics, electrical engineering, nanotechnology, or a related field. Experience with experimental optics, ultrafast lasers, or microwave engineering is highly desirable.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.