Investigating operation of atom interferometers in dynamic inertial conditions

Sedlak, David (2025). Investigating operation of atom interferometers in dynamic inertial conditions. University of Birmingham. Ph.D.

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Abstract

This thesis investigates the operation of atom interferometers in dynamic inertial conditions. As such, the cross-coupling effect of an accelerating sensor head on the output of an interferometer has been simulated, showing a contrast drop to 59% for T = 80 ms and 49% for T = 40 ms if the centre-of-mass of the atoms is within the waist radius of the Raman laser beam. Two ways to combat dynamic conditions are presented. Firstly, a model that is able to simulate phase shear fringes using fluorescence coupled with camera imaging is presented, helping to pave way towards extracting contrast and interferometer phase in one experimental shot. Secondly, a preliminary investigation of multi-modal measurements of gravity, magnetic field and magnetic field gradient is presented. Atom shot noise uncertainties for a T = 50 ms interferometer with 10\(^6\) atoms are estimated as 3 \(\times\) 10\(^-\)\(^8\) ms\(^-\)\(^2\) per shot for gravity and 4 \(\times\) 10\(^-\)\(^6\) Gm\(^-\)\(^1\) per shot for magnetic field gradient.

Experimentally, gravity gradiometer based on atom interferometry has been built. It is capable of producing over 10\(^8\) atoms in the MOT, with cloud temperatures of 7.3 \(\pm\) 0.2 \(\mu\)K for the top chamber and 7.4 \(\pm\) 1.7 \(\mu\)K for the bottom chamber following molasses and state preparation. Interferometry is demonstrated, able to obtain short T gravity fringes without vibration isolation platform. Implementation steps required for phase shear readout are investigated, implementing a beam tilting Raman telescope, camera imaging and building an analysis technique using principal component analysis. The system is integrated with a classical accelerometer and tiltmeter (as well as a linear rail) and is able to obtain Rabi oscillations while moving.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):