Multiphoton dressed Rydberg excitations in a room temperature microwave cavity with ultracold Rb atoms

Luis Gustavo Marcassa Instituto de Física de São Carlos, Universidade de São Paulo

We investigate magneto-optical trap loss spectroscopy of Rydberg excited 85Rb (66 ≤ n ≤ 68 S1/2) atoms, placed inside a room temperature microwave cavity. The cavity frequency at 13.053 GHz is in resonance with the 67S1/2 → 66P3/2 transition, inducing a ladder multiphoton microwave Rydberg absorption and emission. The observed spectra are modeled with an extended Jaynes-Cumming formalism that accounts for multiphoton absorption from and emission into the cavity, the loss from the trap due to Rydberg excitation, and cavity imperfection. We calculate the average photons in each spectral feature and find evidence for fractional photon emission into the cavity modes [1]. The microwave cavity Rydberg spectroscopy in this work should inform the application and technology development of Rydberg based sensors and hybrid Rydberg atom-superconducting resonator quantum gates.

[1] J. D. Massayuki Kondo, Seth T. Rittenhouse, Daniel Varela Magalhães, Vasil Rokaj, S. I. Mistakidis, H. R. Sadeghpour, and Luis Gustavo Marcassa, https://arxiv.org/abs/2407.16819 (2024).