Temporal and Spatial Dependence of Quantum Entanglement from a Field Theory Perspective

Understand

We consider the entanglement dynamics between two Unruh-DeWitt detectors at rest separated at a distance $d$.

• This simple model when analyzed properly in quantum field theory shows many interesting facets and helps to dispel some misunderstandings of entanglement dynamics.
• We find that there is spatial dependence of quantum entanglement in the stable regime due to the phase difference of vacuum fluctuations the two detectors experience, together with the interference of the mutual influences from the backreaction of one detector on the other.
• When two initially entangled detectors are still outside each other's light cone, the entanglement oscillates in time with an amplitude dependent on spatial separation $d$.