  In a recent work, Aharonov et al. suggested that a photon could be separated
from its polarization in an experiment involving pre- and post-selection [New
J. Phys 15, 113015 (2013)]. They named the effect 'quantum Cheshire Cat', in a
reference to the cat that is separated from its grin in the novel Alice's
Adventures in Wonderland. Following these ideas, Denkmayr et al. performed a
neutron interferometric experiment and interpreted the results suggesting that
neutrons were separated from their spin [Nat. Commun. 5, 4492 (2014)]. Here we
show that these results can be interpreted as simple quantum interference, with
no separation between the quantum particle and its internal degree of freedom.
We thus hope to clarify the phenomenon with this work, by removing these
apparent paradoxes.
