arXiv subjects
Publications and source records attributed to M. Chilcott.
We discuss the consequence of excluding allowed RF-transition between substates of a field-dressed Rydberg manifold when predicting the spectrum that will be observed if the dressed system is probed in an optical EIT scheme.
We investigate the Autler-Townes splitting for Rydberg atoms dressed with linearly polarized microwave radiation, resonant with generic $S_{1/2}\leftrightarrow{P}_{1/2}$ and $S_{1/2}\leftrightarrow{P}_{3/2}$ transitions. The splitting is probed using laser light via electromagnetically-induced transparency measurements, where the transmission of probe laser light reveals a two-peak pattern. In particular, this pattern is invariant under rotation of the microwave field polarization. In consequence, we establish $S \leftrightarrow P$ Rydberg transitions as ideally suited for polarization-insensitive electrometry, contrary to recent findings [A. Chopinaud and J.D. Pritchard, Phys. Rev. Appl. $\mathbf{16}$, 024008 (2021)].
We combine a rubidium vapor cell with a corner-cube prism reflector to form a passive RF transducer, allowing the detection of microwave signals at a location distant from the active components required for atomic sensing. This compact transducer} has no electrical components and is optically linked to an active base station by a pair of free-space laser beams that establish an electromagnetically induced transparency scenario. Microwave signals at the transducer location are imprinted onto an optical signal which is detected at the base station. Our sensing architecture with a remote standalone transducer unit adds important flexibility to Rydberg-atom based sensing technologies, which are currently subject to significant attention. We demonstrate a \sim 30 m link with no particular effort and foresee significant future prospects of achieving a much larger separation between the transducer and the base station.
We demonstrate a method to reduce number fluctuations in an ultracold atomic sample using real-time feedback. By measuring the Faraday rotation of an off-resonant probe laser beam with a pair of avalanche photodetectors in a polarimetric setup we produce a proxy for the number of atoms in the sample. We iteratively remove a fraction of the excess atoms from the sample to converge on a target proxy value in a way that is insensitive to environmental perturbations and robust to errors in light polarization. Using absorption imaging for out-of-loop verification, we demonstrate a reduction in the number fluctuations from $3\%$ to $0.45\%$ for samples at a temperature of 16.4 $\mu$K over the time-scale of several hours which is limited by temperature fluctuations, beam pointing noise, and photon shot noise.