  It is well known that the entanglement of a quantum state is invariant under
local unitary transformations. It dictates, for example, that the degree of
entanglement of a photon pair in a Bell state remains maximally entangled
during propagation in free-space. Here we outline a scenario where this
paradigm does not hold. Using local Bell states engineered from classical
vector vortex beams with non-separable degrees of freedom, so-called
classically entangled states, we demonstrate that the entanglement evolves
during propagation, oscillating between maximally entangled (purely vector) and
product states (purely scalar). We outline the theory behind these novel
propagation dynamics and confirm the results experimentally. Crucially, our
approach allows delivering a tunable degree of local entanglement to a distant
receiver by simply altering a modal phase delay holographically, or, in
essence, a tractor beam for entanglement. This demonstration highlights a
hitherto unnoticed property of classical entanglement and offers at the same
time a device for on-demand delivery of vector states to targets, e.g., for
dynamic laser materials processing as well as switchable resolution within STED
systems.
