Nonlinearity of Microwave Electric Field Coupled Rydberg Electromagnetically Induced Transparency and Autler-Townes Splitting

Abstract

An electromagnetically induced transparency (EIT) of a cascade-three-level atom involving Rydberg level in a room-temperature cell, formed with a cesium 6 S 1 / 2 -6 P 3 / 2 -66 S 1 / 2 scheme, is employed to detect the Autler-Townes (AT) splitting resulted with a 15.21-GHz microwave field coupling the 66 S 1 / 2 →65 P 1 / 2 transition. Microwave field induced AT splitting, f A T , is characterized by the distance of peak-to-peak of an EIT-AT spectrum. The f A T dependence on the microwave Rabi frequency, Ω M W , demonstrates two regions, the strong-coupling linear region, f A T ≈ Ω M W and the weak-coupling nonlinear region, f A T ≲ Ω M W . The f A T dependencies on the probe and coupling Rabi frequency are also investigated. Using small probe- and coupling-laser, the Rabi frequency is found to enlarge the linear regime and decrease the uncertainty of the microwave field measurements. The measurements agree with the calculations based on a four-level atomic model.

Improvement of Microwave Electric Field Measurement Sensitivity via Multi-Carrier Modulation in Rydberg Atoms

“…As far as we know, the minimum AT splitting measured previously by the frequency detuning method is 6 MHz [20]. We know that the minimum AT splitting of EIT is limited by the linewidth [25], so the narrow linewidth EIT can be considered to measure the weaker microwave E-field. Therefore, a more weaker microwave E-field can be measured with a narrower EIT linewidth.…”

Terahertz electrometry via infrared spectroscopy of atomic vapor

“…3 are partitioned into the low and high power THz regimes following the definition above by a gray vertical line at P THz = P 0 . On the right-hand side, the THz-induced splitting is twice as large as the THz-free EIT signal linewidth; therefore, AT splitting is dominant and proportional to √ P THz [75]. On the lefthand side, the relationship between f a and √ P THz is not linear, and we discuss the calibration of this power range in Section 3.B.…”

“…√ P THz /P 0 < 1 in Fig. 3, the relationship between the splittings and √ P THz is not linear [65,75], and it is no longer possible to extract an electric field value from the splitting. The deviation from the linear fitting for this low power region is well illustrated in the residual plot in Fig.…”

Discrete time crystal in a finite chain of Rydberg atoms without disorder

“…(1) and (2). Specifically, one may choose to compensate the detuning appearing in the rotating frame expression of H 2 through the AC Stark effect (or Autler-Townes effect), by turning on in the second stage of the Floquet cycle only, i.e., for nT − T 2 t < nT , an additional optical (or microwave) pump which dresses the atom coupling the ground level |g (or the Rydberg level |r ) to an auxiliary excited level |e [63][64][65][66]. This additional pump can be red or blue detuned, the corresponding light shift compensating for of either positive or negative sign, with a detuning absolute value large enough to allow for the adiabatic elimination of level |e .…”