  Entanglement between quantum and classical objects is of special interest in
the context of fundamental studies of quantum mechanics and potential
applications to quantum information processing. In quantum optics, single
photons are treated as light quanta while coherent states are considered the
most classical among all pure states. Recently, entanglement between a single
photon and a coherent state in a free-traveling field was identified to be a
useful resource for optical quantum information processing. However, it was
pointed out to be extremely difficult to generate such states since it requires
a clean cross-Kerr nonlinear interaction. Here, we devise and experimentally
demonstrate a scheme to generate such hybrid entanglement by implementing a
coherent superposition of two distinct quantum operations. The generated states
clearly show entanglement between the two different types of states. Our work
opens a way to generate hybrid entanglement of a larger size and to develop
efficient quantum information processing using such a new type of qubits.
