We demonstrate a new approach for fast preparation, manipulation, and collective readout of an atomic Rydberg-state qubit. By making use of Rydberg blockade inside a small atomic ensemble, we prepare a single qubit within $3\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ with a success probability of ${F}_{p}=0.93\ifmmode\pm\else\textpm\fi{}0.02$, rotate it, and read out its state in $6\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ with a single-shot fidelity of ${F}_{d}=0.92\ifmmode\pm\else\textpm\fi{}0.04$. The ensemble-assisted detection is
103 times faster than imaging of a single atom with the same optical resolution, and enables fast repeated nondestructive measurement. We observe qubit coherence times of $15\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$, much longer than the $\ensuremath{\pi}$ rotation time of 90 ns. Potential applications ranging from faster quantum information processing in atom arrays to efficient implementation of quantum error correction are discussed.
We present the coherent excitation of a single Rubidium atom to the Rydberg state
58d3/2 using a two-photon transition. The experimental setup is described in detail, as are experimental techniques and procedures. The coherence of the excitation is revealed by observing Rabi oscillations between ground and Rydberg states of the atom. We analyze the observed oscillations in detail and compare them to numerical simulations which include imperfections of our experimental system. Strategies for future improvements on the coherent manipulation of a single atom in our settings are given.
We report on the realization of a
133Cs optical tweezer array in a cryogenic blackbody radiation (BBR) environment. By enclosing the array within a 4K radiation shield, we measure long Rydberg lifetimes, up to
406(36)μs for the
55P3/2 Rydberg state, a factor of 3.3(3) longer than the room-temperature value. We employ single-photon coupling for coherent manipulation of the ground-Rydberg qubit. We measure a small differential dynamic polarizability of the transition, beneficial for reducing dephasing due to light intensity fluctuations. Our results pave the path for advancing neutral-atom two-qubit gate fidelities as their error budgets become increasingly dominated by
T1 relaxation of the ground-Rydberg qubit.