CMQED group

Thomas Krieguer

Alexis — 2025-10-20T07:28:42Z

Thomas Krieguer is a PhD student in quantum physics with a Master's degree in Quantum Light-Matter and Nanotechnologies from Paris-Saclay University. With expertise in open quantum systems, non-linear physics, and light-matter interaction, Thomas's research is centered on developing a fully fermionic theoretical model to explore ultra-strong coupling between cavity-mode light and electronic subbands. This advanced model goes beyond the rotating wave approximation to study complex phenomena such as polaritons, the dynamical Casimir effect, and the Bloch-Siegert shift, contributing significantly to the understanding of non-linear generation in cavity-coupled electronic subbands. Thomas's work not only enhances theoretical insights but also aids in predicting and optimizing the responsivity of quantum cascade photodetectors. His model is frequently applied to highly doped semiconductor heterostructures embedded in patch cavities, particularly in quantum cascade detectors, to deepen understanding of electronic transport mechanisms and support the development of enhanced device designs.

Francesco Pisani

Alexis — 2025-10-20T07:28:17Z

Master degree in Plasma Physics and doctorate in Solid State Physics at the University of Pisa. During his postdoctoral research, he was deeply involved in the design, fabrication, and characterization of heterostructures, nano-cavities and metamaterials ; the primary goal being the development of a quantum cascade detector for THz and Mid-IR range, operating in the strong light-matter coupling regime. His expertise comprise measuring the electronic transport by means of spectroscopic techniques : transmission ; absorption ; reflectivity and photocurrent measurements. He was responsible for the fabrication of all the devices in the cleanroom, including lithography of nanostructures and the chemical and dry etching steps. He also contributed in developing a theoretical model to predict the responsivity of these detectors, aiming to further optimize their performance. He also performed multiple simulations involving finite element electromagnetic solvers and Schrödinger-Poisson solver to optimize both the band structure and cavity design.

Usama Iqbal

2025-10-16T09:13:59Z

PhD studying ultra-strong light-matter coupling in THz metamaterials through electrical measurements. His work spans from simulation to characterization, including fabrication processes.
He received his Master's degree in Quantum Devices from Université Paris Cité (formerly Paris 7). During his PhD research, he is deeply involved in investigating ultra-strong light-matter coupling in THz metamaterials through electrical measurements, combining both theoretical and experimental approaches.
His work focuses on the design, fabrication, and characterization of metamaterial structures, aiming to explore fundamental quantum phenomena at terahertz frequencies. He performs various measurements using advanced spectroscopy techniques under cryogenic conditions.
Usama also works with theoretical modeling and simulations to optimize metamaterial designs. Through this comprehensive approach, he aims to advance our understanding of light-matter interactions in the THz regime.