Spatially extended Unruh-DeWitt detectors for relativistic quantum information

TL;DR

This paper introduces a realistic spatially extended Unruh-DeWitt detector model that couples selectively to specific field modes, enabling better analysis of quantum entanglement and noise in relativistic settings.

Contribution

It proposes a finite-size detector with a tailored spatial profile that interacts with peaked mode distributions in inertial and accelerated frames, improving upon point-like models.

Findings

Detector noise depends on acceleration in Minkowski vacuum.

Spatial profile enables selective mode coupling.

Model enhances analysis of entanglement in non-inertial frames.

Abstract

Unruh-DeWitt detectors interacting locally with a quantum field are systems under consideration for relativistic quantum information processing. In most works, the detectors are assumed to be point-like and, therefore, couple with the same strength to all modes of the field spectrum. We propose the use of a more realistic detector model where the detector has a finite size conveniently tailored by a spatial profile. We design a spatial profile such that the detector, when inertial, naturally couples to a peaked distribution of Minkowski modes. In the uniformly accelerated case, the detector couples to a peaked distribution of Rindler modes. Such distributions are of special interest in the analysis of entanglement in non-inetial frames. We use our detector model to show the noise detected in the Minkowski vacuum and in single particle states is a function of the detector's acceleration.