Comment on "Determining angle of arrival of radio-frequency fields using subwavelength, amplitude-only measurements of standing waves in a Rydberg atom sensor"

Abstract

We discuss the consequence of excluding allowed RF-transition between substates of a field-dressed Rydberg manifold when predicting the spectrum that will be observed if the dressed system is probed in an optical EIT scheme.

Figures (4)

• Figure 1: Reproduction of the truncated transition diagram Fig. 6(f) of Ref. Talashila2025 describing RF sensing via Rydberg EIT. The diagram omits the $F=1,2,3$ components of $52D_{5/2}$ Rydberg level and the $F=2$ component of the $53P_{3/2}$ Rydberg level. The $F$-components within each of the these two levels are energetically degenerate, but has been offset vertically to enable visual identification of transitions in play. Red, blue, and orange arrows represent, probe, coupling and RF field transitions, respectively (cf. main text). The area of the arrowheads is proportional to the transition strength.
• Figure 2: Extension of Fig. \ref{['fig:undressed_reduced']} into an untruncated transition diagram. The states with $|m_F| \geq 5$ are shown faded to indicate that they not coupled to the measured probe field in the case where all the polarizations of all the fields are parallel.
• Figure 3: Optical transition diagrams for co-polarized fields with the RF-coupled Rydberg levels represented in a dressed state picture. Result of diagonalizing the RF coupling Hamiltonian for (a) the truncated system in Fig. \ref{['fig:undressed_reduced']} and (b) full system in Fig. \ref{['fig:undressed_full']}. The truncated and full system give rise to 25 and 5 unique eigenenergies, respectively, shown as projections on the right-hand side of the diagrams. The areas of the arrowheads represent the transition strengths and we note that the central states are left uncoupled to the optical fields in both cases.
• Figure 4: Simulated Doppler-free probe transmission when scanning the coupling laser frequency about nominal $6P_{3/2}\leftrightarrow52D_{5/2}$ resonance. Spectra for (a) co-polarized fields and (b) perpendicular RF-optical fields based on full (left-hand column) truncated (right-hand column) transition diagrams are shown. Dashed vertical lines represent the energy eigenvalues of the RF-coupled Rydberg states. The simulations assume radial Rabi frequencies of 0.5, 20, and 200 MHz $\times 2\pi$ for the probe, coupling and RF fields, respectively.