  We propose an experimentally feasible scheme to generate nonmaximal
entanglement between two atomic ensembles. The degree of entanglement is
readily tunable. The scheme involves laser manipulation of atomic ensembles,
adjustable quarter- and half-wave plates, beam splitter, polarizing beam
splitters, and single-photon detectors, and well fits the status of the current
experimental technology. Finally we use the nonmaximally entangled state of
ensembles to demonstrate quantum nonlocality by detecting the
Clauser-Horne-Shimony-Holt inequality.
