arXiv subjects

Jonathan M. H. Gosling

Publications and source records attributed to Jonathan M. H. Gosling.

4 recordsLinked to original sources

arXiv2026

A Penning trap single-photon counter for axion detection

Discovering the microscopic composition of dark matter is one of the most important open problems in physics today. Axions are a leading candidate to be dark matter; however, a search of the full range of all likely axion masses is hampered by the standard quantum noise limit. This makes haloscope searches for axions with masses above 0.1 meV unfeasible with current technologies. To overcome this limitation, we propose a new photon counting technique designed to operate at 30-60 GHz for detecting axions with masses between 0.124 meV and 0.248 meV, based on a single electron in a Penning trap. The electron cyclotron mode absorbs microwave photons, and, via the continuous Stern-Gerlach effect, this absorption imparts a measurable phase shift onto the axial motion. In this paper, we comprehensively analyze this photon detection method. We introduce a new type of fast, phase-sensitive axial detection technique, using axial-magnetron parametric amplification to overcome detector Johnson noise and cancel associated frequency shifts. This method may find other applications in precision Penning trap frequency measurements. We compare the efficiency of the electron single-photon counter with an ideal device, and find that our proposed photon counter has sufficient performance to search for high mass axions.

hep-ph↗

arXiv2025

A Spin-Based Pathway to Testing the Quantum Nature of Gravity

A key open problem in physics is the correct way to combine gravity (described by general relativity) with everything else (described by quantum mechanics). This problem suggests that general relativity and possibly also quantum mechanics need fundamental corrections. Most physicists expect that gravity should be quantum in character, but gravity is fundamentally different to the other forces because it alone is described by spacetime geometry. Experiments are needed to test whether gravity, and hence space-time, is quantum or classical. We propose an experiment to test the quantum nature of gravity by checking whether gravity can entangle two micron-sized crystals. A pathway to this is to create macroscopic quantum superpositions of each crystal first using embedded spins and Stern-Gerlach forces. These crystals could be nanodiamonds containing nitrogen-vacancy (NV) centres. The spins can subsequently be measured to witness the gravitationally generated entanglement. This is based on extensive theoretical feasibility studies and experimental progress in quantum technology. The eventual experiment will require a medium-sized consortium with excellent suppression of decoherence including vibrations and gravitational noise. In this white paper, we review the progress and plans towards realizing this. While implementing these plans, we will further explore the most macroscopic superpositions that are possible, which will test theories that predict a limit to this.

quant-ph↗

arXiv2024

Dark Matter Searches with Levitated Sensors

Motivated by the current interest in employing quantum sensors on Earth and in space to conduct searches for new physics, we provide a perspective on the suitability of large-mass levitated optomechanical systems for observing dark matter signatures. We discuss conservative approaches of recoil detection through spectral analysis of coherently scattered light, enhancements of directional effects due to cross-correlation spectral densities, and the possibility of using quantum superpositions of mesoscopic test particles to measure rare events.

quant-ph↗

arXiv2024

Levitodynamic spectroscopy for single nanoparticle characterisation

Fast detection and characterization of single nanoparticles such as viruses, airborne aerosols and colloidal particles are considered to be particularly important for medical applications, material science and atmospheric physics. In particular, non-intrusive optical characterization, which can be carried out in isolation from other particles, and without the deleterious effects of a substrate or solvent, is seen to be particularly important. Optical characterization via the scattering of light does not require complicated sample preparation and can in principle be carried out in-situ. We describe the characterization of single nanoparticle shape based on the measurement of their rotational and oscillatory motion when optically levitated within vacuum. Using colloidally grown yttrium lithium fluoride nanocrystals of different sizes, trapped in a single-beam optical tweezer, we demonstrate the utility of this method which is in good agreement with simulations of the dynamics. Size differences as small as a few nanometers could be resolved using this technique offering a new optical spectroscopic tool for non-contact characterization of single nanoparticles in the absence of a substrate.

physics.optics↗