Trapped electron for neutrino mass measurement.

Lead Research Organisation: University of Sussex
Department Name: Sch of Mathematical & Physical Sciences

Abstract

This proposal is focused on developing a trapped electron in the geonium chip as an ultra-sensitive detector of microwave radiation for fundamental physics applications. Specifically, in the two years duration of the project, our main goal is to provide a basic experimental proof-of concept of the capacity of our trapped electron (or 'geonium atom') for the planned future measurement of the neutrino's absolute mass scale, m_beta, from the energy endpoint E_0 = 18.6 keV of the Kurie spectrum of the beta-decay of tritium.

The currently ongoing KArslruhe TRItium Neutrino experiment (KATRIN) has recently reported an upper bound of m_beta<1.1 eV/c^2, and it aims at a final accuracy of 0.2 eV/c^2. Neutrino flavour oscillations together with cosmology observations set the ultimate boundary to m_beta>50 meV/c^2, or m_beta>9 meV/c^2 in the case of "inverted" or "normal" ordering of the neutrino mass hierarchy, respectively. These two values define the required accuracy for measuring the neutrino mass. Both are beyond the reach of KATRIN. In order to improve the latter, the novel Cyclotron Resonance Emission Spectroscopy (CRES) technique has been proposed for measuring m_beta. CRES allows for detecting (and counting) beta particles emitted from a radioactive source, such as tritium, and for measuring their kinetic energy. The US-based Project-8 collaboration has demonstrated experimentally the basic principle of CRES, by detecting the microwave radiation emitted by one single beta particle (decayed from gaseous Kripton) and measuring its kinetic energy. With this method, Project-8 aims at a future accuracy in the neutrino mass measurement of 40 meV/c^2. Meanwhile, in early 2021, the Quantum Technologies for Neutrino Mass Measurement (QTNM) consortium, lead by University College London (UCL), has been launched. QTNM is developing a CRES demonstrator apparatus (CRESDA), initially operated with a deuterium source. The ultimate goal is to measure m_beta (eventually within an international collaboration) in a tritium facility, possibly at Culham Centre for Fusion Energy.

While the basic working principle of CRES has been tested, the resolution achieved in the measurement of the kinetic energy of the beta particles amounts to 15 eV/c^2. This is around three orders of magnitude below the required sensitivity for a "guaranteed" measurement of m_beta. This proposal aims at delivering a microwave quantum sensor, the trapped electron, capable of measuring m_beta with the CRES technique, even in the most challenging scenario of "normal" ordering. Within the two years duration of the project we aim at demonstrating an energy resolution of 5 meV/c^2 or better with our geonium microwave sensor. The experiments will be performed at Sussex with an existing geonium chip facility. Our cooperation with the QTNM consortium will provide an external assessment of the suitability of the geonium sensor for measuring m_beta. It will also allow for planning its eventual subsequent integration into the future tritium-ready CRES facility.

Publications

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Lacy J (2024) Circuit Model for HTS Flux Pump With Flux Conservation, Dynamic Resistance, and Flux Flow in IEEE Transactions on Applied Superconductivity

 
Description PhD studentship
Amount £80,000 (GBP)
Organisation Leonardo MW Ltd. 
Sector Private
Country United Kingdom
Start 02/2024 
End 01/2028
 
Description PhD position "Quantum Microwave Illumination with a trapped electron" 
Organisation Leonardo MW Ltd.
Country United Kingdom 
Sector Private 
PI Contribution Sussex funds 2/3 of a PhD position for developing a test of quantum microwave illumination with a trapped electron
Collaborator Contribution Leonardo MW Ltd funds 1/3 of a PhD position for the topic mentioned above.
Impact Collaboration is very recent, has just started, no outcomes yet. It is mainly focused on fundamental research for quantum technology applications. It involves Physics (atomic physics, quantum physics, quantum optics) and engineering (microwave engineering, chip design, RF electronics, MW measurements)
Start Year 2024
 
Title QUANTUM ILLUMINATION USING AN ION TRAP 
Description A quantum illumination apparatus (100) comprises an ion trap (104). The quantum illumination apparatus (100) has a cryogenic cooler (102) in which the ion trap (104) is provided. The ion trap (104) uses electric and magnetic fields to trap an ion and the quantum illumination apparatus (100) is arranged to use the trapped ion to produce a signal photon for use in quantum illumination. The signal photon has correlations with an idler field stored with use of the trapped ion, in the form of a phonon of the trapped ion. A signal photon transmission line (106) extends between the ion trap (104) and an antenna (108). The signal photon may be scattered, e.g. reflected or refracted, by a target object (110) back to the antenna (108), and the transmission line (106) is arranged to transmit the signal photon back to the ion trap (104). The ion trap (104) is arranged to allow the signal photon to interact with the trapped ion and hence the idler field. Specifically, the ion trap (104) is arranged to generate an electrical signal based on correlations between the signal photon and the idler field. The quantum illumination apparatus (100) is arranged to detect reception of the signal photon based on this generated electrical signal. 
IP Reference WO2022234274 
Protection Patent / Patent application
Year Protection Granted 2022
Licensed Yes
Impact Under development, Gola to make a quantum radar. UK is not supporting this research at the moment, it is not included in the National QT programme. Might need to move quantum radar research to a different country (EU, USA).