  Recently, it has been shown that the massless quantum vacuum state contains
entanglement between timelike separated regions of spacetime, in addition to
the entanglement between the spacelike separated regions usually considered.
Here, we show that timelike entanglement can be extracted from the Minkowski
vacuum and converted into ordinary entanglement between two inertial, two-state
detectors at the same spatial location -- one coupled to the field in the past
and the other coupled to the field in the future. The procedure used here
demonstrates a clear time correlation as a requirement for extraction, e.g. if
the past detector was active at a quarter to 12:00, then the future detector
must wait to become active at precisely a quarter past 12:00 in order to
achieve entanglement.
