The 27th International Conference on Atomic Physics

Slow atoms traverse an optical cavity field: diffusive atomic motion

Not scheduled

1h 30m

Abstract of recent or ongoing work (by remote / virtual participant) Quantum optics and hybrid quantum systems Abstracts by remote participants

Description

We investigate the atomic motion while single, laser-cooled ${}^{87}$Rb atoms propagate through a high-finesse cavity. Generating a cold trapped atomic ensemble 4-mm above the cavity [J. Kim${}^{\ast }$, K. Kim${}^{\ast }$ et al., Sensors 21, 6255 (2021)], the trap is released, and single atoms fall through the resonator mode by gravity. Strong atom-cavity interaction causes large decreases in the transmission of a weak resonant probe field. In order to understand the various magnitudes of the transmission reduction, we perform numerical calculation of the Itô stochastic differential equations for atomic motion [A. Doherty et al., Phys. Rev. A 63, 013401 (2000)]. The calculation shows that the atomic trajectory is strongly diffusive along the cavity axis, which averages the spatially modulated atom-cavity coupling constant in this direction. Therefore, we would attribute the atom-by-atom difference of the transmission change to the different atomic arrival position along the transverse mode direction.

In addition, we demonstrate a dipole trap of single atoms with an intracavity field. We also present a precise characterization of our optical resonator, resulting in the estimation of the atom-cavity coupling constant up to four significant figures [D. Lee et al., Opt. Continuum 1, 603 (2022)].

Figure 1 (a) Experimental setup. Single Photon Counting Module (SPCM). (b) Probe transmission drops when single atoms traverse the resonant cavity mode. (c) Simulation result of atomic trajectory.