INSPIRE Physical Sciences: Levitation-based quantum gravimeter

The main aim of our research project is to design and demonstrate a prototype of a portable device that exploits quantum properties to measure gravitational fields with high accuracy. Miniaturization will be achieved by putting in place a genuine paradigm shift, namely the change of the main mechanism used to measure gravity with quantum systems: we will use the gravity-dependent phase acquired by an oscillating optically-levitated quantum system. This is in stark contrast with previous proposals based on the free fall of matter-like systems. While the first design will assume a classical framework where gravity is assumed Newtonian, we will develop new technology aimed at detecting, for the first time, general relativistic effects. We will consider two experimental platforms. The first employs an optically-levitated nanodiamond that contains a nitrogen-vacancy (NV) centre. This setup has the advantage that it operates at room temperature. The second is a cold-atom setup that provides a natural arena to extend the proposal to the general relativistic regime. We will assess thoroughly, both experimentally and theoretically, the effects of potential systematic errors and noise sources in both setups.

This project is based on fundamental physics but is tightly focused on solving an important technological problem: how to detect gravity sensitively. If the project goals are met they would lead to a commercially valuable device which would create value for UK PLC. Our research is ambitious and novel so may not lead to the gravimeter that we envision. However, the applications of a gravimeter which improves on existing devices would be numerous. The biggest financial impact would be from the ability to sense petroleum reserves due to their density differing from surrounding rock. Similarly, the military are keen to be able to sense nuclear submarines with gravimeters. Both of these users are prepared to pay a premium for the best device available. By ensuring that this research is developed in the UK, employment, investment and taxes would be generated. One by-product of IK's simulation work on this project is expected to be a better understanding of clinical magnetic resonance imaging (MRI) which would be beneficial to the health of us all, as well as being commercially significant for the healthcare sector.
Three further types of impact will emerge from this project: enhancing the knowledge base that underpins future technological achievements, engaging the public with science and working scientists and training of the next generation of researchers in transferable skills valued by academia and industry.
The understanding of quantum attributes that this project requires is pivotal to exploiting them optimally in any form of future sensing or information technology. Beyond the above, for designing any nanotechnological device, be it a motor or a small engine, we will need to thoroughly understand the extent to which they should be modelled quantum mechanically.
We collaborate with large and small companies that are aligned to our research. For example, within this current project, GM will extend his work with E6 (a UK-based company with over 3000 employees), who develop high-tech applications of diamonds. E6 have been providing GM with research-grade diamonds containing spin qubits for three years, and would be keen to bring diamond qubits to market if possible.
Another area of impact for our research is in engaging the public with science. We have substantial experience in this area. We give public talks related to our research such as GM's 2013 "Warwick Physics Christmas Lecture" attended by over 360 people and recently posted on YouTube. GM was also part of the team which brought the 2011 exhibit "Schrodinger's Cat on a Silicon Chip" to the Royal Society Summer Science Exhibition. The exhibition attracted 6000 people over the week it was running.
Finally, this project will provide training and development opportunities for young researchers. In our project, the students and PDRAs will learn not only the skills needed individually for experiments and theory but also how the two work together. Presentation and writing skills will be honed as they prepare reports of their work and present talks and posters. Furthermore, the multi-site structure of the project will develop skills in teamworking and collaboration. All of these skills are transferable and highly valued in industry.