Speaker
Description
The Quantum enhanced particle astrophysics (QuEPA) project attempts to use an electron Penning trap as one part of a detector for axion dark matter [1]. Axions emerged as a dark matter candidate after initially being proposed to resolve the observed lack of charge parity (CP) violation in the strong interaction. Axions can convert into microwave photons in the presence of a strong magnetic field due to their coupling to the electromagnetic field [2]. A microwave single photon counter dramatically improves the scanning rate of an axion detector [3]. As no technology currently exists to efficiently detect photons in the frequency band of 30-60 GHz, we propose the use of a single electron in a Penning trap as a microwave photon counter. Incoming photons are absorbed by the electron's cyclotron motion, which, through the continuous Stern-Gerlach effect, produces a detectable phase shift in the axial oscillation.
In this session, we present an update on the progress towards realising this detector. We have designed and built a novel cryogenic Penning trap system housed within a dilution refrigerator capable of reaching temperatures below 50 millikelvin. We have developed a custom impedance-matched image-current detection system featuring GaAs semiconductor switches, allowing electronic switching between detection and cooling modes, laying the groundwork for cooling the electron below its ambient temperature. We have successfully trapped clouds of around 500 electrons on demand and are currently performing initial trap characterisation measurements, with preliminary dark matter searches and phase-sensitive detection of the axial motion as the next steps.
[1] J. A. Devlin, M. L. Wojtkowiak, S. R. Banhatti, H. Zhang, J. Shi, T. S. Dofher, J. M. H. Gosling, M. R. Tarbutt, and R. C. Thompson, A Penning trap single-photon counter for axion detection, arXiv:2601.05472 (2026).
[2] I. G. Irastorza and J. Redondo, New experimental approaches in the search for axion-like particles, Prog. Part. Nucl. Phys. 102, 89 (2018).
[3] S. K. Lamoreaux, et al., Phys. Rev. D 88, 035020 (2013).
| Academic level | PhD student |
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