Description of the thesis topic

There is a general consensus that only a tiny fraction of the matter and energy present in the Universe has so far been identified. Highlighting and characterizing these constituents is one of the major challenges of physics. The paradigm of axions, hypothetical particles proposed in the 1970s in the context of high energy physics, is particularly promising.
However, the detection of this “dark” matter remains a challenge for standard measurement techniques due to the weakness of the expected signals. During this thesis work, we propose to test the axion paradigm over a wide range of masses through the use of quantum microwave amplification techniques. These techniques make it possible to explore quantities with a precision only limited by the Heisenberg uncertainty principle. In particular, we will use a detector or "haloscope" of a new principle, which we began to develop very recently. This detector has several advantages compared to those already used in the literature. In particular, this type of halide is phase-resolved, which makes it possible to detect weak microwave signals in a time 4 to 5 orders of magnitude shorter [Cottet,Kontos:24] than traditional haloscopes. Furthermore, thanks to the use of magnetic elements [Théry, Fruy:24] and superconducting circuits resilient to the magnetic field [Théry et al., PRB'24], we hope to be able to considerably extend the test mass range of the axion paradigm, which would have very important consequences on our understanding of the universe and particle physics beyond the standard model.

Work Context

The techniques used in this work will mainly be microwave measurements at very low temperatures, time domain manipulation of quantum binary units, nanofabrication, vacuum techniques as well as theoretical techniques such as density matrix theory. and numerical simulations of the evolution of quantum systems.

Constraints and risks

cryogenics, chemical, electrical