TY  - JOUR
AU  - Agullo, I.
AU  - Bonga, B.
AU  - Ribes-Metidieri, P.
AU  - Kranas, D.
AU  - Nadal-Gisbert, S.
PY  - 2023
DA  - 2023//
TI  - How ubiquitous is entanglement in quantum field theory?
T2  - Phys. Rev. D
JO  - Physical Review D
SP  - 085005
EP  - 25pp
VL  - 108
IS  - 8
PB  - Amer Physical Soc
AB  - It is well known that entanglement is widespread in quantum field theory, in the following sense: every Reeh-Schlieder state contains entanglement between any two spatially separated regions. This applies, in particular, to the vacuum of a noninteracting scalar theory in Minkowski spacetime. Discussions on entanglement in field theory have focused mainly on subsystems containing infinitely many degrees of freedom-typically, the field modes that are supported within a compact region of space. In this article, we study entanglement in subsystems made of finitely many field degrees of freedom, in a free scalar theory in D + 1-dimensional Minkowski spacetime. The focus on finitely many modes of the field is motivated by the finite capabilities of real experiments. We find that entanglement between finite-dimensional subsystems is not common at all, and that one needs to carefully select the support of modes for entanglement to show up. We also find that entanglement is increasingly sparser in higher dimensions. We conclude that entanglement in Minkowski spacetime is significantly less ubiquitous than normally thought.
SN  - 2470-0010
UR  - https://arxiv.org/abs/2302.13742
UR  - https://doi.org/10.1103/PhysRevD.108.085005
DO  - 10.1103/PhysRevD.108.085005
LA  - English
N1  - WOS:001157784100011
ID  - Agullo_etal2023
ER  -