  We investigate various aspects of capacity of entanglement in certain setups
whose entanglement entropy becomes extensive and obeys a volume law. In
particular, considering geometric decomposition of the Hilbert space, we study
this measure both in the vacuum state of a family of non-local scalar theories
and also in the squeezed states of a local scalar theory. We also evaluate
field space capacity of entanglement between interacting scalar field theories.
We present both analytical and numerical evidences for the volume law scaling
of this quantity in different setups and discuss how these results are
consistent with the behavior of other entanglement measures including Renyi
entropies. Our study reveals some generic properties of the capacity of
entanglement and the corresponding reduced density matrix in the specific
regimes of the parameter space. Finally, by comparing entanglement entropy and
capacity of entanglement, we discuss some implications of our results on the
existence of consistent holographic duals for the models in question.
