Rydberg EIT in High Magnetic Field

Travis Nicholson, Jeff Thompson, Qiyu Liang +6 more

Hong Cheng, H. M. Wang, S. S. Zhang +3 more

We have studied the high resolution spectroscopy of Rydberg state 87Rb in a ladder-type electromagnetically induced transparency (EIT) configuration at room temperature. A highly excited Rydberg atom is nearly degenerate for its hyperfine states but this degeneracy will be broken by an applied magnetic field, resulting in a spectral splitting in a coupled basis. In our ladder-type EIT experiment, we observed the high resolution spectral splitting of Rydberg atoms in an external magnetic field with two different optical polarization combinations of σ+ − σ+ and σ+ − σ− for probe and coupling laser beams. A strict theory has been set up to explain the observed spectral line position and intensity accurately considering the Zeeman effects of three EIT-concerned states all in the coupled basis. Specially for the Rydberg state, we can transform its wavefunction back into the decoupled basis for the spectral line assignment.

Yuqing Liu, Jianan Zhang, Yu-Xiang Wang +5 more

We report the Rydberg electromagnetically induced transparency (EIT) spectra of the 87 Rb 5 S 1/2 → 5 P 3/2 → 5 D 5/2 → 38 F 7/2 transition in a vapor cell with a DC magnetic field and demonstrate its use for tunable, resonant L-band microwave electric field detection via the Autler-Townes (AT) splitting. Compared to conventional two-photon Rydberg excitation, three-photon EIT exhibits a markedly richer and more intricate spectral structure resulting from extra transition pathways under a DC magnetic field. Under copropagating linearly-polarized optical fields and a static magnetic field, we resolve as many as eight distinct EIT peaks and extract their linear Zeeman-shift coefficients. The measured Zeeman-shifts are all in agreement with the predictions of a simple analytical equation. More interestingly, we demonstrate a single-Zeeman-sublevel Rydberg excitation using three-photon EIT with circular light fields and a quantization axis. We subsequently exploit single-Zeeman-sublevel Rydberg-EIT at the low principal quantum number n = 38 to perform a tunable, resonant EIT–AT measurement of 1.5 GHz (L-band) microwave electric fields. The observed characteristics confirm that L-band microwave measurement via three-photon excited low- n F Rydberg states is advantageous by avoiding the autoionization and high laser power demands of two-photon excited high- n Rydberg states.

S. Feneuille

Eliane Luc-Koenig, J. M. Lecomte

Hsuan-Jui Su, Jia-You Liou, I-Chun Lin +1 more

We present Rydberg-state electromagnetically-induced-transparency (EIT) measurements examining the effects of laser polarization, magnetic fields, laser intensities, and the optical density of the thermal 87 Rb medium. Two counter-propagating laser beams with wavelengths of 480 nm and 780 nm were employed to sweep the spectrum across the Rydberg states |33 D 3/2 〉 and |33 D 5/2 〉. An analytic transmission expression well fits the Rydberg-EIT spectra with multiple transitions under different magnetic fields and laser polarization after accounting for the relevant Clebsch-Gordan coefficients, Zeeman splittings, and Doppler shifts. In addition, the high-contrast Rydberg EIT can be optimized with the probe laser intensity and optical density. Rydberg EIT peak height was achieved at 13%, which is more than twice as high as the maximum peak height at room temperature. A quantitative theoretical model is employed to represent the spectra properties and to predict well the optimization conditions. A Rydberg EIT spectrum with high contrast in real time can be served as a quantum sensor to detect the electromagnetic field within an environment.