Coherence of a dynamically decoupled single neutral atom

摘要

Long qubit coherence and efficient atom-photon coupling are essential for advanced applications in quantum communication. One technique to maintain coherence is dynamical decoupling (DD), where a periodic sequence of refocusing pulses is employed to reduce the interaction of the system with the environment. We experimentally study the implementation of DD on an optically trapped, spin-polarized Rb-87 atom. We use the two magnetic-sensitive 5S(1/2) Zeeman levels vertical bar F = 2, m(F)= -2 > and vertical bar F = 1, m(F) = -1 > as qubit states, motivated by the possibility of coupling vertical bar F = 2, m(F) = -2 > to 5P(3/2) the excited state vertical bar F' = 3, m(F)' = -3 > via a closed optical transition. With more refocusing pulses in the DD technique, we manage to extend the coherence time from 38(3) mu s to around 7 ms. We also observe a strong correlation between the motional states of the atom and the qubit coherence after the refocusing, which can be used as a measurement basis to resolve trapping parameters. (C) 2021 Optical Society of America