Adsorbate dynamics on a silica-coated gold surface measured by Rydberg Stark spectroscopy

Abstract

Trapping a Rydberg atom close to a surface is an important step towards the realisation of many proposals of quantum information or hybrid quantum systems. One of the challenges in these experiments is to overcome the electric field emanating from contaminations on the surface. Here we report on measurements of an electric field created by 87 Rb atoms absorbed on a 25 nm thick layer of SiO 2 , covering a 90 nm layer of Au. The electric field is measured using a two-photon transition to the 23D 5/2 and 25S 1/2 state. The electric field value that we measure is higher than typical values measured above metal surfaces, but is consistent with other measurements above SiO 2 surfaces. In addition, we measure the temporal behaviour of the field and observe that we can reduce it in a single experimental cycle, using UV light or by mildly heating the surface, whereas the buildup of the field takes thousands of cycles. We explain these results by a change in the ad-atoms distribution on the surface. These results indicate that the stray electric field can be reduced, opening new possibilities for experiments with trapped Rydberg atoms near surfaces. † Present address: CQ Center for Collective Quantum Phenomena and Their Applications,

Intracavity Rydberg-atom electromagnetically induced transparency using a high-finesse optical cavity

“…7. In a recent experimental study, we arrived at a similar conclusion after a detailed study of the adsorbate electric field caused by Rb atoms on a quartz surface [50,60,61]. In support of this assertion, we were able to change the size of the electric field when the EIT coupling laser beam was misaligned so that it was scattering o↵ one of the cavity mirrors.…”

Controlling stray electric fields on an atom chip for experiments on Rydberg atoms

“…In previous experiments we observed large stray electric fields above a gold surface [27] and even ∼ 10 times larger fields above silica-coated gold [12]. However, in other studies [16] significant reduction of the stray electric field was achieved by forced desorption of the ad-atoms.…”

Scanning Quantum Cryogenic Atom Microscope

“…Electric fields from surface charges can be detected [7]. Such fields may arise from adsorbed Rb atoms, which can pose a difficulty for various applications [38,[58][59][60][61][62][63][64][65]. The electric field is due to an induced dipole whose magnitude varies depending on surface properties.…”