Optimal State Choice for Rydberg-Atom Microwave Sensors

Abstract

Rydberg electromagnetically induced transparency (EIT) enables realization of atom-based SI-traceable microwave (MW) sensing, imaging and communication devices by exploiting the strong microwave electric dipole coupling of highly excited Rydberg states. Essential to the development of robust devices is a careful characterization of sensor performance and systematic uncertainties. In this work we present a comparison of microwaveinduced EIT splitting in a cesium atomic vapor for four possible Rydberg couplings 65S 1/2 → 65P 1/2 , 66S 1/2 → 66P 3/2 , 79D 5/2 → 81P 3/2 and 62D 5/2 → 60F 7/2 at microwave transition frequencies around 13 GHz. Our work highlights the impact of multi-photon couplings to neighbouring Rydberg states in breaking both the symmetry and linearity of the observed splitting, with excellent agreement between experimental observations and a theoretical model accounting for multi-photon couplings. We identify an optimal angular state choice for robust microwave measurements, as well as demonstrating a new regime in which microwave polarization can be measured.

Sensitivity improvement of Rydberg atom-based microwave sensing via electromagnetically induced transparency

“…2(b). The quality of the linearity of the measurements is also very good, excluding the complex state interaction induced nonlinearity [34]. Therefore, the weak RF E-field value can be obtained by the above formula at given antenna power.…”

“…The enhancement of dynamic optical response by RF detuning can be understood by a theoretical simulation based on the optical Bloch equation considering the four energy levels [10,11,13,22,34,36]. Taking the energy level of the intermediate state 5P 3/2 as a reference, the Hamiltonian H can be expressed as a matrix form…”

Bright and dark Autler-Townes states in the atomic Rydberg multilevel spectroscopy

“…In the AT experiments conducted in Refs. [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23] the detection of Rydberg atoms by electromagnetically induced transparency (EIT) optical spectroscopy or selective electric field ionisation allows the experimentalists to probe the frequency and amplitude of the mw driving radiation. The mw field amplitude is derived from the AT modification of the Rydberg excitation.…”

“…When one transition is driven by a intense laser, the second transition spectrum is composed by a resonant doublet with the separation between the two components determined by the laser electric field. This process, well characterised in atomic/molecular and solid state spectroscopy, has received recently a new interest within a different context: the precise determination of a microwave (mw) field amplitude for calibration purposes as in [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. The mw radiation is applied to cold atoms in Rydberg states where the electric dipole moment is very large, such that even a weak mw field produces AT splitting.…”

Microwave-optical coupling via Rydberg excitons in cuprous oxide

“…To connect these two regimes, a hybrid quantum system allowing efficient conversion between optical and microwave frequencies is required [10,11]. Microwave to optical conversion has been demonstrated to varying degrees using mechanical oscillators [12,13], nonlinear crystals [14] and Rydberg atoms [15][16][17][18][19].…”