Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2006.13917 · Physical review. D/Physical review. D.

Field assisted extraction and swelling of quantum coherence for moving Unruh-DeWitt detectors

Nikolaos K. Kollas, Dimitris Moustos, Kostas Blekos

Published Sep 28, 2020• 12 citations
arXivHTMLPDF

Abstract

We study the effects of motion, on the amount of coherence extracted onto an Unruh-DeWitt detector, modeled as a two-level system, when it interacts with a massless scalar coherent field in $1+1$ Minkowski spacetime. We observe that compared to a detector at rest, for certain values of the initial energy of the field and the duration of the interaction, the amount extracted is larger for a detector moving with constant speed or uniform acceleration. This ``swelling'' of coherence becomes more intense for increasing values of its velocity and acceleration, and is mostly observed for short interaction durations, when the energy of the field is larger compared to that of the detector, and for longer interaction durations but smaller field energies. As a consequence, the rate at which coherence is lost, is sometimes slower for a moving detector than for a detector at rest.

DOI
10.1103/physrevd.102.065020

Related papers

Generation and catalysis of coherence with scalar fields

Nikolaos K. Kollas, Dimitris Moustos

Employing time-dependent perturbation theory, we discuss the conditions under which a spatially extended two level Unruh-DeWitt detector, coupled to the proper time derivative of a scalar field, can drive itself into a coherent superposition of its energy basis. It is shown that this process, which is assisted due to the energy cost required for the implementation of the interaction, is only possible for a field with a nonzero coherent amplitude distribution. When the detector interacts instantaneously with the field through a delta coupling, the latter acts as a catalyst resulting in the extraction of the same amount of coherence each time at the cost of a positive amount of work. For a Gaussian smeared detector and a field in a coherent state the amount generated to lowest order in the coupling constant depends on the phase of the amplitude distribution, the initial energy of the field, the mean radius of the detector and the mean interaction duration between the two. We observe that for a detector moving at a constant velocity and with a mean radius of the same order as its transition wavelength, coherence swelling effects are present the intensity of which depends on the dimension of the underlying Minkowski spacetime.

arXiv:2103.09165•Physical review. D/Physical review. D.•Jan 6, 2022•10 citations

Entanglement dynamics for Unruh-DeWitt detectors interacting with massive scalar fields: the Unruh and anti-Unruh effects

Yuebing Zhou, Jiawei Hu, Hongwei Yu

Abstract We study, in the framework of open quantum systems, the entanglement dynamics for a quantum system composed of two uniformly accelerated Unruh-Dewitt detectors interacting with a bath of massive scalar fields in the Minkowski vacuum. We find that the entanglement evolution for the quantum system coupled with massive fields is always slower compared with that of the one coupled with massless fields, and this time-delay effect brought about by the field being massive can however be counteracted by a large enough acceleration, in contrast to the case of a static quantum system in a thermal bath, where this time delay is not affected by the temperature. Remarkably, the maximal concurrence of the quantum system generated during evolution may increase with acceleration for any inter-detector separation while that for static ones in a thermal bath decreases monotonically with temperature, and this can be considered as an anti-Unruh effect in terms of the entanglement generated.

arXiv:2105.14735•Journal of High Energy Physics•Sep 1, 2021•36 citations

Entanglement harvesting of inertially moving Unruh-DeWitt detectors in Minkowski spacetime

Cendikiawan Suryaatmadja, Robert B. Mann, Wan Cong

We investigate the effects of relative motion on entanglement harvesting by considering a pair of Unruh-Dewitt detectors moving at arbitrary but independent and constant velocities, both linearly interacting with a massless scalar field vacuum in four-dimensional Minkowski spacetime. Working within the weak coupling approximation, we find that the negativity is a (nonelementary) function of the relative velocity of the detectors, as well as their energy gaps and minimal separation. We find parameter regions where negativity increases with velocity up to a maximum and then decreases, reaching zero at some sublight velocity. At any given relative velocity, the harvested entanglement is inversely correlated with the detector energy gap (at sufficiently high values) and the distance of closest approach of two detectors.

arXiv:2205.14739•Physical review. D/Physical review. D.•Oct 11, 2022•15 citations

Entangled Unruh–DeWitt detectors amplify quantum coherence

Shu-Min Wu, Yu-Xuan Wang, Wentao Liu

Abstract We explore the quantum coherence between a pair of entangled Unruh–DeWitt detectors, interacting with a quantum field, using a nonperturbative approach in a (3+1)-dimensional Minkowski spacetime with instantaneous switching ( $$\delta $$ δ -switching). It is intriguing to observe that for a maximally entangled state, increasing the coupling strength enhances the detectors’ initial quantum coherence while simultaneously causing a monotonic decrease in their initial entanglement. This reveals a remarkable phenomenon: through nonperturbative interactions, entangled Unruh–DeWitt detectors can exhibit a dual effect-amplifying quantum coherence while degrading quantum entanglement. This finding stands in stark contrast to previous studies based on perturbative methods or Gaussian switching functions, which generally concluded that interactions between detectors and the field lead to a simultaneous degradation of quantum coherence and entanglement due to environmental decoherence. Notably, while initially separable detectors successfully harvest quantum coherence from the vacuum, entanglement extraction remains fundamentally prohibited. These contrasting behaviors underscore the fundamental distinction between coherence and entanglement as quantum resources, and highlight their complementary roles in field-detector interactions.

arXiv:2506.14115•The European Physical Journal C•Oct 3, 2025•7 citations

Transition rates and their applications in accelerated single-qubit for fermionic spinor field coupling

Arnab Mukherjee, Sunandan Gangopadhyay, P. H. M. Barros +1 more

In this work, we investigate the interaction between a uniformly accelerated single qubit and a fermionic spinor field. Here we consider both the massless and the massive fermionic spinor fields. The qubit-field interaction occurs over a finite time and was evolved via perturbation theory. This approach yields the transition probability rates, from which we subsequently evaluate the quantum coherence of an Unruh-DeWitt (UDW) detector initially prepared in a qubit state. Our findings reveal that the UDW detector responds more when coupled with the fermionic field, and consequently, quantum coherence (for the fermionic case) degrades much more rapidly when compared to the case of the qubit linearly coupled with the scalar field. Moreover, the analysis suggests that particle mass plays a protective role against Unruh-induced decoherence as the rest mass energy becomes comparable to the detector's energy-level spacing, the detector's excitation probability and response decreases, which leads to the mitigation of quantum coherence degradation in accelerated quantum systems.

quant-pharXiv:2512.09144•Dec 11, 2025•0 citations

Coherence revival under the Unruh effect and its metrological advantage

Jiafan Wang, Jingjun Zhang, Jun Min Feng

Abstract In this paper, we investigate the quantum coherence extraction between two accelerating Unruh–DeWitt detectors, coupling to a scalar field in (3 + 1)-dimensional Minkowski spacetime. We find that quantum coherence as a nonclassical correlation can be generated through the Markovian evolution of the detector system, just like quantum entanglement. However, with growing Unruh temperature, in contrast to monotonously degrading entanglement, we find that quantum coherence exhibits a striking revival phenomenon. For certain detectors’ initial state choices, the coherence measure will reduce to zero at first and then grow to an asymptotic value. We verify such coherence revival by inspecting its metrological advantage on the quantum Fisher information (QFI) enhancement. Since the maximal QFI bounds the accuracy of quantum parameter estimation, we conclude that the extracted coherence can be utilized as a physical resource in quantum metrology.

arXiv:2111.01358•Communications in Theoretical Physics•Dec 16, 2024•3 citations
We study the effects of motion, on the amount of coherence extracted onto an Unruh-DeWitt detector, modeled as a two-level system, when it interacts with a massless scalar coherent field in 1+11+11+1 Minkowski spacetime. We observe that compared to a detector at rest, for certain values of the initial energy of the field and the duration of the interaction, the amount extracted is larger for a detector moving with constant speed or uniform acceleration. This ``swelling'' of coherence becomes more intense for increasing values of its velocity and acceleration, and is mostly observed for short interaction durations, when the energy of the field is larger compared to that of the detector, and for longer interaction durations but smaller field energies. As a consequence, the rate at which coherence is lost, is sometimes slower for a moving detector than for a detector at rest.
Employing time-dependent perturbation theory, we discuss the conditions under which a spatially extended two level Unruh-DeWitt detector, coupled to the proper time derivative of a scalar field, can drive itself into a coherent superposition of its energy basis. It is shown that this process, which is assisted due to the energy cost required for the implementation of the interaction, is only possible for a field with a nonzero coherent amplitude distribution. When the detector interacts instantaneously with the field through a delta coupling, the latter acts as a catalyst resulting in the extraction of the same amount of coherence each time at the cost of a positive amount of work. For a Gaussian smeared detector and a field in a coherent state the amount generated to lowest order in the coupling constant depends on the phase of the amplitude distribution, the initial energy of the field, the mean radius of the detector and the mean interaction duration between the two. We observe that for a detector moving at a constant velocity and with a mean radius of the same order as its transition wavelength, coherence swelling effects are present the intensity of which depends on the dimension of the underlying Minkowski spacetime.
Abstract We study, in the framework of open quantum systems, the entanglement dynamics for a quantum system composed of two uniformly accelerated Unruh-Dewitt detectors interacting with a bath of massive scalar fields in the Minkowski vacuum. We find that the entanglement evolution for the quantum system coupled with massive fields is always slower compared with that of the one coupled with massless fields, and this time-delay effect brought about by the field being massive can however be counteracted by a large enough acceleration, in contrast to the case of a static quantum system in a thermal bath, where this time delay is not affected by the temperature. Remarkably, the maximal concurrence of the quantum system generated during evolution may increase with acceleration for any inter-detector separation while that for static ones in a thermal bath decreases monotonically with temperature, and this can be considered as an anti-Unruh effect in terms of the entanglement generated.
We investigate the effects of relative motion on entanglement harvesting by considering a pair of Unruh-Dewitt detectors moving at arbitrary but independent and constant velocities, both linearly interacting with a massless scalar field vacuum in four-dimensional Minkowski spacetime. Working within the weak coupling approximation, we find that the negativity is a (nonelementary) function of the relative velocity of the detectors, as well as their energy gaps and minimal separation. We find parameter regions where negativity increases with velocity up to a maximum and then decreases, reaching zero at some sublight velocity. At any given relative velocity, the harvested entanglement is inversely correlated with the detector energy gap (at sufficiently high values) and the distance of closest approach of two detectors.
Abstract We explore the quantum coherence between a pair of entangled Unruh–DeWitt detectors, interacting with a quantum field, using a nonperturbative approach in a (3+1)-dimensional Minkowski spacetime with instantaneous switching ( δ\delta δ δ -switching). It is intriguing to observe that for a maximally entangled state, increasing the coupling strength enhances the detectors’ initial quantum coherence while simultaneously causing a monotonic decrease in their initial entanglement. This reveals a remarkable phenomenon: through nonperturbative interactions, entangled Unruh–DeWitt detectors can exhibit a dual effect-amplifying quantum coherence while degrading quantum entanglement. This finding stands in stark contrast to previous studies based on perturbative methods or Gaussian switching functions, which generally concluded that interactions between detectors and the field lead to a simultaneous degradation of quantum coherence and entanglement due to environmental decoherence. Notably, while initially separable detectors successfully harvest quantum coherence from the vacuum, entanglement extraction remains fundamentally prohibited. These contrasting behaviors underscore the fundamental distinction between coherence and entanglement as quantum resources, and highlight their complementary roles in field-detector interactions.
In this work, we investigate the interaction between a uniformly accelerated single qubit and a fermionic spinor field. Here we consider both the massless and the massive fermionic spinor fields. The qubit-field interaction occurs over a finite time and was evolved via perturbation theory. This approach yields the transition probability rates, from which we subsequently evaluate the quantum coherence of an Unruh-DeWitt (UDW) detector initially prepared in a qubit state. Our findings reveal that the UDW detector responds more when coupled with the fermionic field, and consequently, quantum coherence (for the fermionic case) degrades much more rapidly when compared to the case of the qubit linearly coupled with the scalar field. Moreover, the analysis suggests that particle mass plays a protective role against Unruh-induced decoherence as the rest mass energy becomes comparable to the detector's energy-level spacing, the detector's excitation probability and response decreases, which leads to the mitigation of quantum coherence degradation in accelerated quantum systems.
Abstract In this paper, we investigate the quantum coherence extraction between two accelerating Unruh–DeWitt detectors, coupling to a scalar field in (3 + 1)-dimensional Minkowski spacetime. We find that quantum coherence as a nonclassical correlation can be generated through the Markovian evolution of the detector system, just like quantum entanglement. However, with growing Unruh temperature, in contrast to monotonously degrading entanglement, we find that quantum coherence exhibits a striking revival phenomenon. For certain detectors’ initial state choices, the coherence measure will reduce to zero at first and then grow to an asymptotic value. We verify such coherence revival by inspecting its metrological advantage on the quantum Fisher information (QFI) enhancement. Since the maximal QFI bounds the accuracy of quantum parameter estimation, we conclude that the extracted coherence can be utilized as a physical resource in quantum metrology.