Optimising Atom Interferometers for Prospective Commercial Quantum-based Devices
David Elcock, University of Southampton, UK
Group meeting via video conference (Zoom)
Tuesday, December 7, 9:00 am (MEZ)
Due to the Covid-19 pandemic, we are still holding our group seminars and journal clubs via video conference.This procedure enables us to continue our research, enhance discussions and exchange important information.
Atom interferometers are instruments that promise to offer devices greater sensitivity in measuring observables such as rotation, speed, acceleration, magnetic field, etc: As these interferometers make use of quantum effects however, they typically utilise several technologies including ultra-high vacuum chambers, RF electronic servos, laser systems and more making them rather complex. To advance the development of future commercial quantum devices, the UK goverment therefore launched the $120M UK Quantum Technology Programme. This programme was divided into four hubs: Sensors & Timing, Computing & Simulations, Imaging and Communication with each hub attempting to solve the challenges that currently limit the scope of quantum devices. In this talk we will focus on the work relating to the Sensors & Timing hub at the Universityof Southampton where we focused on enhancing the performance of atom interferometers. In particular focus will be set on the work relating to so-called composite mirror pulses custom designed using optimal control theory and tested in our lab. Towards the end of the talk we will highlight three other techniques we worked on: a mini frequency comb, speckle-based spectrometers (theoretical) and hardware enhancements for an upcoming atomic-based rotation sensor. The use of optimal control theory allows us to adapt the composite pulse technique from Nuclear Magnetic Resonance physics to help reduce the sensitivity of our interferometers against perturbations (e:g: noise) in two experimental variables: laser power and laser detuning. The aim is to optimise interferometric signal output over a larger variation in these variables so that quantum devices becomes less sensitive to systematic errors from experimental imperfections and from their surroundings. Whilst experiments are currently limited to individual mirror pulses, current work of the group focuses on extending this adaptation to composite beamsplitter pulses, interferometric sequences and more complex composite pulse shapes.
 J. C. Saywell, I. Kuprov, D. Goodwin, M. Carey & T. Freegarde, 'Optimal control of mirror pulses for cold-atom interferometry', PRA 98 023625, (2018).
 M. Carey, J. Saywell, M. Belal & T. Freegarde, 'Velocimetry of cold atoms by matter-wave interferometry', PRA 99 023631, (2019).
 J. Saywell, M. Carey, M. Belal, I. Kuprov and T. Freegarde, 'Optimal control of Raman pulse sequences for atom interferometry', J. Phys. B: At. Mol. Opt. Phys. 55 085006, (2020).
 D. E. Elcock, 'General Enhancements of Atom Interferometers', University of Southampton Eprints Repository 452262, MPhil thesis, (2021).
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