Field theoretical few-mode models for cavity atom interferometry

Seminar author:Nikolija Momčilović

Event date and time:03/08/2024 04:00:pm

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Raman diffraction of atoms is commonly used as π/2- and π-pulses in atom interferometry. Such pulses constitute the analogue to beam splitters and mirrors in optical interferometers. In practice these transitions are driven by intense laser light, and thus the light field is approximately in a mixture of coherent states with random phase. Consequently, quantization effects from the electromagnetic field [1, 2] are averaged out due to the broad photon distribution in such beams. However, technological progress moves towards the use of optical cavities due to their superior beam quality. Moreover, recently there has been a substantial effort [3, 4] towards, and a first demonstration [5] of atom interferometry with motionally entangled atoms in a cavity. With these new tools, one can imagine interferometers where quantization effects of the light and matter system become relevant [6] or even dominant [1, 2]. Such systems will make a field theoretical description necessary for the joint system and in this way also provide a proper accounting of the entanglement dynamics between light, motional and internal degrees of freedom of the typically bosonic atoms. Currently, general models are rare and specific ones are tailor made [5], with an explicit experiment in mind. A more generic approach would thus be helpful. We pursue this task via a few-mode field theory coupled to the electromagnetic field. In particular, we show how an open-field theory describing a two-photon Rabi model with center-of-mass dynamics can be derived via averaging [7].

[1] K. Soukup et al., J. Chem. Phys. 154, 164310 (2021)
[2] T. Aßmann et al., Phys. Rev. Research 4, 013115 (2022)
[3] K. Lange et al., Science 360, 6387 416-418 (2018)
[4] F. Anders et al., Phys. Rev. Letters 127, 140402 (2021)
[5] G. P. Greve et al., Nature 610, 472-477 (2022)
[6] N. Momcilovi ˇ c, B. Sc. thesis, Ulm University (2022)
[7] O. Gamel et al., Phys. Rev. A 82, 052106 (2010)