  Inspired by the recent developments in the research of atom-photon quantum
interface and energy-time entanglement between single photon pulses, we propose
to establish the concept of a special energy-time entanglement between a single
photon pulse and internal states of a single atom, which is analogous to the
frequency-bin entanglement between single photon pulses. We show that this type
of entanglement arises naturally in the interaction between frequency-bin
entangled single photon pulse pair and a single atom, via straightforward
atom-photon phase gate operations. We also discuss the properties of this type
of entanglement and show a preliminary example of its potential application in
quantum networking. Moreover, a quantum entanglement witness is constructed to
detect such entanglement from a reasonably large set of separable states.
