Autler-Townes spectroscopy of a Rydberg ladder

Journal Article · Thu Jan 01 00:00:00 EST 2026 · Physical Review A (PRA)

DOI:https://doi.org/10.1103/gj9l-m7hh· OSTI ID:3025139

Xiang, Tai; Lu, Yue-Hui; Ho, Jacquelyn; Lee, Tsai-Chen; Yan, Zhenjie; Stamper-Kurn, Dan M

Ladder-type two-photon excitation of an atom from a ground state |g〉, to an intermediate excited state |e〉, and finally, to a Rydberg state |r〉 has a variety of uses from quantum information to sensing. A common scheme for detecting this transition optically is through electromagnetically induced transparency (EIT). However, in inverted wavelength schemes, where the ground-to-excited transition wavelength is shorter than the excited-to-Rydberg transition wavelength, the strength of the EIT feature on the lower-leg beam is strongly reduced in a Doppler-broadened medium. Here, we report on an alternative two-photon spectroscopic feature, which we term the two-photon Autler-Townes resonance, observed on the upper-leg beam. Compared to the EIT signal, this feature's superior signal-to-noise ratio allows one to resolve Rydberg resonances with principal quantum number as high as n=80. We also show that such a feature can be utilized to generate an error signal for stabilizing the frequency of the upper-leg beam.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: US Department of Energy; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Materials Sciences & Engineering Division (SC-22.2)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 3025139
• Journal Information: Physical Review A (PRA), Journal Name: Physical Review A (PRA) Journal Issue: 1 Vol. 113
• Country of Publication: United States
• Language: English