  The spin-wave (SW) NOON state is an $N$-particle Fock state with two atomic
spin-wave modes maximally entangled. Attributed to the property that the phase
is sensitive to collective atomic motion, the SW NOON state can be utilized as
a novel atomic interferometer and has promising application in quantum enhanced
measurement. In this paper we propose an efficient protocol to
deterministically produce the atomic SW NOON state by employing Rydberg
blockade. Possible errors in practical manipulations are analyzed. A feasible
experimental scheme is suggested. Our scheme is far more efficient than the
recent experimentally demonstrated one, which only creates a heralded
second-order SW NOON state.
