Fig. 4: Probing ϕ.
From: Ultrafast energy exchange between two single Rydberg atoms on a nanosecond timescale
a, The Ramsey pump–probe sequence. b, Ramsey fringes for Jt = 0.1π, π, 2π (R = 5, 2.4, 1.9 μm) when one (grey circles) or two (red circles) atoms are loaded in a pair of tweezers. The fine delay offset is arbitrarily defined to be 0 fs in each interferogram. c, CR and θR extracted from b with numerical simulations. Calculations are represented by lines, whereas measurements are represented by points. Error bars are the s.e.m. from the fitting routine of the Ramsey fringes. d, Bloch sphere representation of the state of atom 1, which remains in state \(\left|e\right\rangle +\left|d\right\rangle\) when atom 2 is in state \(\left|e\right\rangle\), but is driven into \(\left|e\right\rangle +| c| {e}^{i\phi }\left|d\right\rangle\) when atom 2 is in state \(\left|d\right\rangle\). Trajectories are shown for three scenarios depending on the parameters (J, V, ΔE) illustrated in e: resonant energy exchange V = ΔE = 0 (red arrow), real parameters (J, V, ΔE)/(2π) = (75, −23, −8) MHz at R = 2.4 μm (blue arrow) and with envisioned active correction ΔE = −V (green arrow).
