Unruh effect for detectors in superposition of accelerations

Author(s)
Luis C. Barbado, Esteban Castro-Ruiz, Luca Apadula, Časlav Brukner
Abstract

The Unruh effect is the phenomenon that accelerated observers detect particles even when inertial observers experience the vacuum state. In particular, uniformly accelerated observers are predicted to measure thermal radiation that is proportional to the acceleration. Here we consider the Unruh effect for a detector that follows a quantum superposition of different accelerated trajectories in Minkowski spacetime. More precisely, we analyze the excitations of a pointlike multilevel particle detector coupled to a massless real scalar field and moving in the superposition of accelerated trajectories. We find that the state of the detector excitations is, in general, not a mere (convex) mixture of the thermal spectrum characteristics of the Unruh effect for each trajectory with well-defined acceleration separately. Rather, for certain trajectories and excitation levels, and upon the measurement of the trajectory state, the state of the detector excitations features in addition off-diagonal terms. The off-diagonal terms of these "superpositions of thermal states" are related to the distinguishability of the different possible states in which the field is left after its interaction with detector's internal degrees of the freedom.

Organisation(s)
Research Network Quantum Aspects of Space Time, Quantum Optics, Quantum Nanophysics and Quantum Information
External organisation(s)
Université Libre de Bruxelles, Österreichische Akademie der Wissenschaften (ÖAW)
Journal
Physical Review D
Volume
102
Pages
045002
No. of pages
16
ISSN
2470-0010
DOI
https://doi.org/10.1103/PhysRevD.102.045002
Publication date
08-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
103024 Quantum field theory, 103028 Theory of relativity
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/e4762655-6079-437e-b742-1c7feaec7630