Entanglement generation between atomic ensembles is typically modeled using the framework of continuous
variables (CV) which approximates discrete spin operators as canonical position and momentum operators.
Although hugely successful with many applications, this approximation is valid only for small deviations in spin.
Here we investigate entanglement generation between two atomic ensemble qubits using a measurement based
scheme of a common light mode. Various methods of entanglement detection of the entangled state is discussed.
We propose a entanglement witness for this state and discuss its further applications to optical states.
We propose criteria and experimental strategies to realise the Einstein-Podolsky-Rosen (EPR) steering nonlocality.
One-way steering can be obtained where there is asymmetry of thermal noise on each system. We also
present EPR steering inequalities that act as signatures and suggest how to optimise EPR correlations in specific
schemes so that the genuine multipartite EPR steering nonlocality (EPR paradox) can also possibly be realised.
The results presented here also apply to the spatially separated macroscopic atomic ensembles.