Fig. 3: Cooperative response after a coherent drive of the ancilla.
From: A subwavelength atomic array switched by a single Rydberg atom
a, Ancilla \(\left\vert {g}^{{\prime} }\right\rangle \leftrightarrow \left\vert P\right\rangle\) Rabi oscillations obtained from ground state \(\left\vert {g}^{{\prime} }\right\rangle\) fluorescence detection by varying the length of the UV pulse before probing (see Fig. 1c for the protocol). Applying a damped sinusoidal fit, we find a Rabi frequency of ΩUV/2π = 1.22(2) MHz and a decay constant of τdecay = 6(3) μs. b,c, The transmittance (b) and reflectance (c) data follow the Rabi oscillation of the ancilla. The solid lines in b and c represent the best fit results, with the amplitude of the oscillation and overall offset as the only fit parameters, while the oscillation frequency and decay time are fixed and taken from a. The three insets in c indicate spatially averaged reflection images for ΩUVt = 0, π and 2π, respectively, with an indicated region of interest of 5 μm × 5 μm. The dashed line in c illustrates the expected transmission signal for an ancilla Rydberg fraction of \({P}_{\left\vert P\right\rangle }=0.96\). The solid grey line represents the resonance reflection signal (0.16(3)) from isotropic scattering. The latter was measured experimentally by introducing vertical disorder by means of Bloch oscillations (Supplementary Information). The measurements are averages over 120–170 independent repetitions. Error bars denote the s.e.m.
