Locality and entanglement harvesting in covariantly bandlimited scalar fields

TL;DR

This paper investigates how a covariant bandlimit, representing a minimal length scale, affects quantum entanglement harvesting and communication, revealing nonlocality and acausal effects due to the Lorentz-invariant cutoff.

Contribution

It introduces a covariant bandlimit in quantum fields and analyzes its impact on entanglement and causality, highlighting novel nonlocal and acausal phenomena.

Findings

Covariant bandlimit induces nonlocality in quantum fields.

It causes acausal communication effects.

Modifies virtual particle behavior under the cutoff.

Abstract

Considerations of high energies in quantum field theories on smooth manifolds have led to generalized uncertainty principles and the possibility of a physical minimal length in quantum gravitational scenarios. In these models, the minimal length would be a physical limit, not just a mathematical tool, and should be Lorentz invariant. In this paper, we study two-qubit communication and entanglement harvesting in a field subject to a covariant bandlimit (minimum length) and present the changes induced by this bandlimit. We find the bandlimit introduces nonlocality and acausal communication in a manner unlike non-covariant bandlimits or other quantum optical approximations. We also observe that this covariant bandlimit introduces uncertainties in time and temporal ordering with the unusual behavior attributed to the behavior of virtual particles being modified by the covariant cutoff.