Two-photon microwave transitions and strong-field effects in a room-temperature Rydberg-atom gas

Abstract

We investigate two-photon Autler-Townes splitting and strong-field effects of 85 Rb Rydberg atoms in a room-temperature vapor cell. To observe the level structure we employ electromagnetically induced transparency. We first study the two-photon 62S 1/2 -63S 1/2 microwave transition using an electric-field reference measurement obtained with the one-photon 62S 1/2 -62P 3/2 transition. We then study the 61D 5/2 -62D 5/2 transition where the microwave electric-field range is extended up to ∼ 40 V/m. A Floquet analysis is used to model field-induced level shifts and state-mixing effects present in the strongly driven quantum systems under consideration. Calculations are found to be in good agreement with experimental observations.

Radio-frequency-modulated Rydberg states in a vapor cell

“…Additionally, avoided crossings (such as those in the m j =3/2 line at 16 dBi in figure 3(b)) could be better resolved. Unlike in previous measurements [2,3], in the present setup the inhomogeneity of the RF field has a negligible effect on the experimental line-widths. This is because the diameter of the probe region ( m 70 m) is much smaller than the RF wavelength ( 3 m) and because the RF field does not vary significantly along the length of the cell (7.5 cm) which is smaller than the length of the electrode plates (see figure 1(a)).…”

“…A similar treatment is used in [21]. The implemented Floquet method has previously been established as a suitable means to model Rydberg-atom microwave spectra in vapor cell experiments [2,3].…”

“…Recently there has been a growing interest in using electromagnetically induced transparency (EIT) with Rydberg atoms to study atomic spectra in microwave fields and, conversely, to employ the atomic response to measure properties of the field. Developments include measurements of weak and strong microwave electric fields (ranging from ∼1 mV m −1 [1] up to 230 V m −1 [2,3]), microwave polarization measurements [4], and subwavelength imaging [5,6]. These efforts are further motivated by a broader initiative towards establishing atomic measurement standards for field quantities [1,7,8].…”

Spectroscopy of cesium Rydberg atoms in strong radio-frequency fields

“…The method has previously been described in Refs. [16,17]. Here, we provide the most relevant results.…”

Annulled van der Waals interaction and fast Rydberg quantum gates

“…In order to implement the C Z gate, a microwave source induces a fast transition from |1 to another Rydberg state |2 [37][38][39][40][41], such that |2, 2 experiences a large blockade shift B due to the vdWI. Accessing the state |2, 2 is subject to an error due to its Rydberg blockade shift, but this error is suppressed with moderately large microwave field strengths.…”