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 nonc...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.展开更多
Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field ...Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field in Minkowski spacetime,whose response spectrum exhibits an intermediate statistics of(1+1)anyon field.We find that comparing to an inertial moving detector,the GP in accelerating frame is modified after the nonunitary evolution of the detector due to the Unruh effect.We show that such modification can distinguish the different thermalizing ways of the detector,which depends on the scaling dimension of the conformal primary field.Finally,we estimate the difference between the GP under the Unruh radiation and that in a thermal bath for a static observer,which reveals the quantum origin of the Unruh effect rather than a conventional thermal noise.展开更多
We study spontaneous excitation of both a static detector （modelled by a two-level atom） immersed in a thermal bath and a uniformly accelerated one in the Minkowski vacuum interacting with a real massive scalar fiel...We study spontaneous excitation of both a static detector （modelled by a two-level atom） immersed in a thermal bath and a uniformly accelerated one in the Minkowski vacuum interacting with a real massive scalar field. Our results show that the mass of the scalar field manifests itself in the spontaneous excitation rate of the static detector in a thermal bath （and in vacuum） in the form of a selection rule for transitions among states of the detector. However, this selection rule disappears for the accelerated ones, demonstrating that an accelerated detector does not necessarily behave the same as an inertial one in a thermal bath. We lind the imprint left by the mass is the appearance of a grey-body factor in the spontaneous excitation and de-excitation rates, which maintains the detailed balance condition between them and thus ensures a thermal equilibrium at the Unruh temperature the same as that of the massless case. We also analyze quantitatively the effect of the mass on the rate of change of the detector＇s energy and find that when the mass is very small, it only induces a small negative correction. However, when it is very large, it then exponentially damps the rate, thus essentially forbidding any transitions among states of the detector.展开更多
The Unruh effect predicts an astonishing phenomenon that an accelerated detector would detect counts despite being in a quantum field vacuum in the rest frame.Since the required detector acceleration for its direct ob...The Unruh effect predicts an astonishing phenomenon that an accelerated detector would detect counts despite being in a quantum field vacuum in the rest frame.Since the required detector acceleration for its direct observation is prohibitively large,recent analog studies on quantum simulation platforms help to reveal various properties of the Unruh effect and explore the notyet-understood physics of quantum gravity.To further reveal the quantum aspect of the Unruh effect,analogous experimental exploration of the correlation between the detector and the field,and the consequences for coherent quantum trajectories of the detector without classical counterparts,are essential steps but are currently missing.Here,we utilize a laser-controlled trapped ion to experimentally simulate an oscillating detector coupled with a cavity field.We observe joint excitation of both the detector and the field in the detector's frame,coincide with the coordinated dynamics predicted by the Unruh effect.Particularly,we simulate the detector moving in single and superposed quantum trajectories,where the latter case shows coherent interference of excitation.Our demonstration reveals properties of quantum coherent superposition of accelerating trajectories associated with quantum gravity theories that have no classical counterparts,and may offer a new avenue to investigate phenomena in quantum field theory and quantum gravity.We also show how a generalization of the method and results in this work may be beneficial for direct observation of the Unruh effect.展开更多
The Unruh effect is one of the most fundamental manifestations of the fact that the particle content of a field theory is observer dependent. However, there has been so far no experimental verification of this effect,...The Unruh effect is one of the most fundamental manifestations of the fact that the particle content of a field theory is observer dependent. However, there has been so far no experimental verification of this effect, as the associated temperatures lie far below any observable threshold. Recently, physical phenomena, which are of great experimental challenge, have been investigated by quantum simulations in various fields. Here we perform a proof-of-principle simulation of the evolution of ferrnionic modes under the Unruh effect with a nuclear magnetic resonance （NMR） quantum simulator. By the quantum simulator, we experimentally demonstrate the behavior of Unruh temperature with acceleration, and we fiarther investigate the quantum correlations quantified by quantum discord between two fermionic modes as seen by two relatively accelerated observers. It is shown that the quantum correlations can be created by the Unrtfia effect from the classically correlated states. Our work may provide a promising way to explore the quantum physics of accelerated systems.展开更多
Einstein’s equivalence principle allows one to compare the magnitudes of a gravitational acceleration field with the magnitudes of a field of Unruh acceleration temperatures. The validity of such a comparison is demo...Einstein’s equivalence principle allows one to compare the magnitudes of a gravitational acceleration field with the magnitudes of a field of Unruh acceleration temperatures. The validity of such a comparison is demonstrated by using it to derive the effective Hawking black body radiation at a Schwarzschild black hole horizon. One can then extend the black hole thought experiment to a Hawking-Unruh temperature equation expressed in terms of the Schwarzschild radius. This follows an inverse radius law rather than an inverse radius-squared law. Following a brief discussion of current theoretical failures to explain galactic rotation curves, the Unruh acceleration temperature equations are brought together to show how a rotating supermassive black hole galactic system should follow an inverse radius rule of centripetal gravitational force and centripetal acceleration. This result appears to indicate that galactic observations currently attributed to dark matter may in part be attributed to classical Newtonian dynamics superimposed on a relativistic rotating system powered by a supermassive black hole.展开更多
Considering the spin degree of freedom of the Dirac field, we study the entanglement behavior of a different class of communication channel and teleportation of three-dimensional single particle state in noninertial f...Considering the spin degree of freedom of the Dirac field, we study the entanglement behavior of a different class of communication channel and teleportation of three-dimensional single particle state in noninertial frames. Numerical analysis shows that the communication channel in our scheme can offer enough distillable entanglement for the teleportation protocol. Moreover, the teleportation protocol could work well if Rob＇s acceleration is not very big, but the fidelity of the teleportation is still reduced due to the Unruh effect.展开更多
We introduce a kind of number-conserving coherent state in Rindler space which can describe the quantum state of thermal particles observed in Rindler space. This is based on the Unruh effect that the thermal particle...We introduce a kind of number-conserving coherent state in Rindler space which can describe the quantum state of thermal particles observed in Rindler space. This is based on the Unruh effect that the thermal particles seen by an accelerating observer in fiat space can be seen by an inertial observer in curved space under a conformal transformation.展开更多
The fine-grained uncertainty relation (FUR) is investigated for accelerating open quantum system, which manifests the celebrated Unruh effect, a crucial piece of the jigsaw for combining relativity and quantum physics...The fine-grained uncertainty relation (FUR) is investigated for accelerating open quantum system, which manifests the celebrated Unruh effect, a crucial piece of the jigsaw for combining relativity and quantum physics. For a single detector, we show that the inevitable Unruh decoherence can induce a smaller FUR uncertainty bound, which indicates an additional measurement uncertainty may exist. For an open system combined with two detectors, via a nonlocal retrieval game, the related FUR uncertainty bound is determined by the non-classical correlation of the system. By estimating the maximal violation of Bell inequality for an accelerating system, we show that the FUR uncertainty bound can be protected from Unruh decoherence, due to quantum correlation generated through Markovian dynamics.展开更多
Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,ins...Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,instead of the traditional single-mode approximation method in the relativistic setting.We find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of acceleration.Meanwhile,our results also reveal the interesting behavior of the Gaussian steering asymmetry,which increases for a specific range of accelerated parameter and then gradually approaches to a finite value.Such finding is well consistent and explained by the well-known Unruh effect,which could significantly destroy the one-side Gaussian quantum steering.Finally,our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites,since the effects of acceleration are equal to the effects of gravity according to the equivalence principle.展开更多
It is well known that the quantum fluctuation of entanglement(QFE) between Unruh–De Witt detector(modeled by a two-level atom) is always investigated in a relativistic setting. However, both of the Unruh radiation an...It is well known that the quantum fluctuation of entanglement(QFE) between Unruh–De Witt detector(modeled by a two-level atom) is always investigated in a relativistic setting. However, both of the Unruh radiation and quantum fluctuation effects play an important role in precise measurements of quantum entanglement. In this paper, we have quantitatively analyzed how the relativistic motion affects the QFE for two entangled Unruh–De Witt detectors, one of which is accelerated and interacting with the neighbor external scalar field. Our results show that the QFE, which initially increases by the Unruh thermal noise, will suddenly decay when the acceleration reaches to a considerably large value. Therefore, the relativistic effect will lead to non-negligible QFE effect. We also find that the initial QFE(without acceleration effect) reaches its minimum value at the maximally entangled state and the separable state. More importantly, our analysis demonstrates that although the QFE has a huge decay when the acceleration is greater than ~ 0.96, the ratio of △E/C is still very large, due to the simultaneous decay of concurrence to a very low value. Finally, enlightened by the well-known equivalence principle,we discuss the possibility of applying the above findings to the dynamics of QFE under the influence of gravitation field.展开更多
<p align="justify"> <span style="font-family:Verdana;">In this note, we propose that an object moving with proper constant acceleration, i.e., a Rindler observer experiences a sublimati...<p align="justify"> <span style="font-family:Verdana;">In this note, we propose that an object moving with proper constant acceleration, i.e., a Rindler observer experiences a sublimation (or evaporation) process. In this first proposal, we do not consider the backreaction due to the sublimation. We focus on charged matter particles for the discussion, but for simplicity, we present the quantization of the neutrally charged massive scalar field in Rindler space. The amplitude from the Minkowski observer perspective of detection of matter particles that have been emitted by a Rindler observer, or accelerated detector, is computed in a new fashion. We make a comparison between the Rindler observer sublimation and the black hole evaporation. We present three variants of a new experimental setup, and we show that in two of them, the Minkowski amplitude of detection of matter particles corresponds to that of a thermal process. There is one, however, where deviations from thermality can be found. It is numerically explored.</span> </p>展开更多
In the framework of open quantum systems,we study the dynamics of an accelerated quantum battery(QB),modeled as an Unruh-DeWitt detector interacting with a real massless scalar quantum field.The QB is driven by an ext...In the framework of open quantum systems,we study the dynamics of an accelerated quantum battery(QB),modeled as an Unruh-DeWitt detector interacting with a real massless scalar quantum field.The QB is driven by an external classical force acting as a charger.A major challenge in this setup is the environment-induced decoherence,which leads to energy dissipation of the QB.Accelerated motion exacerbates this dissipation,manifesting effects analogous to those experienced by a static QB in a thermal bath in free space,consistent with the Unruh effect.To overcome these challenges,we introduce a reflecting boundary in a space,which modifies the vacuum fluctuations of the field and leads to a position-dependent suppression of dissipation for the Unruh-DeWitt QB.Our analysis reveals that as the QB approaches the boundary,the relevant dissipation is significantly reduced.In particular,when the QB is placed extremely close to the boundary,the dissipation is nearly eliminated,as if the QB were a closed system.Furthermore,we identify a characteristic length scale associated with the acceleration of QB.When the distance between the QB and the boundary is much smaller than this scale,the boundary effectively suppresses dissipation,and this suppression effect becomes identical for both an accelerated QB and a static QB in a thermal bath.Conversely,when the distance is beyond this scale,the suppression effect weakens and manifests a significant difference between these two cases.Our findings demonstrate the potential of boundary-induced modifications in vacuum fluctuations to effectively suppress dissipation,offering valuable insights for optimizing QB performance.This work paves the way for the development of high-efficiency quantum energy storage systems in the relativistic framework.展开更多
The fluctuation and relative fluctuation of entanglement entropy of a bipartite system for Dirac fields in noninertial frames are investigated. It is shown that the fluctuation and relative fluctuation of entanglement...The fluctuation and relative fluctuation of entanglement entropy of a bipartite system for Dirac fields in noninertial frames are investigated. It is shown that the fluctuation and relative fluctuation of entanglement entropy are observer-dependent, which depend on their observed frames. It is found that both the fluctuation and relative fluctuation of entanglement entropy become more noticeable with the increasing of the subsystem's acceleration. We also find that the entanglement entropy always has fluctuation regardless of the initial state parameter and for any magnitude of the acceleration. We argue that the statistical mean for the measurement of entanglement entropy relates to the accelerated motion of the observer.展开更多
The restoration of spontaneous symmetry breaking for a scalar field theory for an accelerated observer is discussed by the one-loop effective potential calculation and by considering the effective potential for compos...The restoration of spontaneous symmetry breaking for a scalar field theory for an accelerated observer is discussed by the one-loop effective potential calculation and by considering the effective potential for composite operators. Above a critical acceleration, corresponding to the critical restoration temperature, Tc, for a Minkowski observer by Unruh relation, i.e. ac/2π=Tc, the symmetry is restored. This result confirms other recent calculations in effective field theories that symmetry restoration can occur for an observer with an acceleration larger than some critical value. From the physical point of view, a constant acceleration mimics a gravitational field and the critical acceleration to restore the spontaneous symmetry breaking corresponds to a huge gravitational effect which prevents boson condensation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12075178,12475061)Shaanxi Fundamental Science Research Project for Mathematics and Physics(No.23JSY006)the Innovation Program for Quantum Science and Technology(2021ZD0302400)。
文摘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.
基金Project supported by the National Natural Science Foundation of China(Grant No.12075178)Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2018JM1049)。
文摘Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field in Minkowski spacetime,whose response spectrum exhibits an intermediate statistics of(1+1)anyon field.We find that comparing to an inertial moving detector,the GP in accelerating frame is modified after the nonunitary evolution of the detector due to the Unruh effect.We show that such modification can distinguish the different thermalizing ways of the detector,which depends on the scaling dimension of the conformal primary field.Finally,we estimate the difference between the GP under the Unruh radiation and that in a thermal bath for a static observer,which reveals the quantum origin of the Unruh effect rather than a conventional thermal noise.
基金Supported in part by the National Natural Science Foundation of China under Grant Nos. 11075083,10935013 and 11005013the Zhejiang Provincial Natural Science Foundation of China under Grant No. Z6100077+3 种基金the National Basic Research Program of China under Grant No. 2010CB832803the PCSIRT under Grant No. IRT0964the Research Foundation of Education Bureau of Hunan Province under Grant No. 10C0377Provincial Natural Science Foundation of China under Grant No. 11JJ700
文摘We study spontaneous excitation of both a static detector （modelled by a two-level atom） immersed in a thermal bath and a uniformly accelerated one in the Minkowski vacuum interacting with a real massive scalar field. Our results show that the mass of the scalar field manifests itself in the spontaneous excitation rate of the static detector in a thermal bath （and in vacuum） in the form of a selection rule for transitions among states of the detector. However, this selection rule disappears for the accelerated ones, demonstrating that an accelerated detector does not necessarily behave the same as an inertial one in a thermal bath. We lind the imprint left by the mass is the appearance of a grey-body factor in the spontaneous excitation and de-excitation rates, which maintains the detailed balance condition between them and thus ensures a thermal equilibrium at the Unruh temperature the same as that of the massless case. We also analyze quantitatively the effect of the mass on the rate of change of the detector＇s energy and find that when the mass is very small, it only induces a small negative correction. However, when it is very large, it then exponentially damps the rate, thus essentially forbidding any transitions among states of the detector.
基金supported by the National Natural Science Foundation of China(Grant No.92165206)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301603)supported by the Scientific Research Start-Up Funds of Hangzhou Normal University(Grant No.4245C50224204016)。
文摘The Unruh effect predicts an astonishing phenomenon that an accelerated detector would detect counts despite being in a quantum field vacuum in the rest frame.Since the required detector acceleration for its direct observation is prohibitively large,recent analog studies on quantum simulation platforms help to reveal various properties of the Unruh effect and explore the notyet-understood physics of quantum gravity.To further reveal the quantum aspect of the Unruh effect,analogous experimental exploration of the correlation between the detector and the field,and the consequences for coherent quantum trajectories of the detector without classical counterparts,are essential steps but are currently missing.Here,we utilize a laser-controlled trapped ion to experimentally simulate an oscillating detector coupled with a cavity field.We observe joint excitation of both the detector and the field in the detector's frame,coincide with the coordinated dynamics predicted by the Unruh effect.Particularly,we simulate the detector moving in single and superposed quantum trajectories,where the latter case shows coherent interference of excitation.Our demonstration reveals properties of quantum coherent superposition of accelerating trajectories associated with quantum gravity theories that have no classical counterparts,and may offer a new avenue to investigate phenomena in quantum field theory and quantum gravity.We also show how a generalization of the method and results in this work may be beneficial for direct observation of the Unruh effect.
基金the National Key Basic Research Program of China (Grant Nos. 2013CB921800 and 2014CB848700)the National Natural Science Foundation of China (Grant Nos. 11227901, 91021005, 11375167, 11374308, 11104262 and 11275183)the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB01030400)
文摘The Unruh effect is one of the most fundamental manifestations of the fact that the particle content of a field theory is observer dependent. However, there has been so far no experimental verification of this effect, as the associated temperatures lie far below any observable threshold. Recently, physical phenomena, which are of great experimental challenge, have been investigated by quantum simulations in various fields. Here we perform a proof-of-principle simulation of the evolution of ferrnionic modes under the Unruh effect with a nuclear magnetic resonance （NMR） quantum simulator. By the quantum simulator, we experimentally demonstrate the behavior of Unruh temperature with acceleration, and we fiarther investigate the quantum correlations quantified by quantum discord between two fermionic modes as seen by two relatively accelerated observers. It is shown that the quantum correlations can be created by the Unrtfia effect from the classically correlated states. Our work may provide a promising way to explore the quantum physics of accelerated systems.
基金supported by the National Key R&D Program of China (2021YFC2203100)the National Natural Science Foundation of China (11961131007, 11653002)+4 种基金the Fundamental Research Funds for the Central Universities(WK2030000044)the CSC Innovation Talent Fundsthe CAS Project for Young Scientists in Basic Research (YSBR-006)the USTC Fellowship for International Cooperationthe USTC Research Funds of the Double First-Class Initiative。
文摘Einstein’s equivalence principle allows one to compare the magnitudes of a gravitational acceleration field with the magnitudes of a field of Unruh acceleration temperatures. The validity of such a comparison is demonstrated by using it to derive the effective Hawking black body radiation at a Schwarzschild black hole horizon. One can then extend the black hole thought experiment to a Hawking-Unruh temperature equation expressed in terms of the Schwarzschild radius. This follows an inverse radius law rather than an inverse radius-squared law. Following a brief discussion of current theoretical failures to explain galactic rotation curves, the Unruh acceleration temperature equations are brought together to show how a rotating supermassive black hole galactic system should follow an inverse radius rule of centripetal gravitational force and centripetal acceleration. This result appears to indicate that galactic observations currently attributed to dark matter may in part be attributed to classical Newtonian dynamics superimposed on a relativistic rotating system powered by a supermassive black hole.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11064016 and 61068001)
文摘Considering the spin degree of freedom of the Dirac field, we study the entanglement behavior of a different class of communication channel and teleportation of three-dimensional single particle state in noninertial frames. Numerical analysis shows that the communication channel in our scheme can offer enough distillable entanglement for the teleportation protocol. Moreover, the teleportation protocol could work well if Rob＇s acceleration is not very big, but the fidelity of the teleportation is still reduced due to the Unruh effect.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10775097 and 10874174by the Specialized Research Fund for the for the Doctorial Progress of Higher Education of China under Grant No.20070358009
文摘We introduce a kind of number-conserving coherent state in Rindler space which can describe the quantum state of thermal particles observed in Rindler space. This is based on the Unruh effect that the thermal particles seen by an accelerating observer in fiat space can be seen by an inertial observer in curved space under a conformal transformation.
基金Project supported by the National Natural Science Foundation of China(Grant No.12075178)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2018JM1049).
文摘The fine-grained uncertainty relation (FUR) is investigated for accelerating open quantum system, which manifests the celebrated Unruh effect, a crucial piece of the jigsaw for combining relativity and quantum physics. For a single detector, we show that the inevitable Unruh decoherence can induce a smaller FUR uncertainty bound, which indicates an additional measurement uncertainty may exist. For an open system combined with two detectors, via a nonlocal retrieval game, the related FUR uncertainty bound is determined by the non-classical correlation of the system. By estimating the maximal violation of Bell inequality for an accelerating system, we show that the FUR uncertainty bound can be protected from Unruh decoherence, due to quantum correlation generated through Markovian dynamics.
基金Project supported by National Key R&D Program of China(Grant No.2017YFA0402600)the National Natural Science Foundation of China(Grant Nos.11690023,11373014,and 11633001)+2 种基金Beijing Talents Fund of Organization Department of Beijing Municipal Committee of the CPCthe Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB23000000)the Interdiscipline Research Funds of Beijing Normal University。
文摘Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,instead of the traditional single-mode approximation method in the relativistic setting.We find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of acceleration.Meanwhile,our results also reveal the interesting behavior of the Gaussian steering asymmetry,which increases for a specific range of accelerated parameter and then gradually approaches to a finite value.Such finding is well consistent and explained by the well-known Unruh effect,which could significantly destroy the one-side Gaussian quantum steering.Finally,our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites,since the effects of acceleration are equal to the effects of gravity according to the equivalence principle.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0402600)the National Natural Science Foundation of China(Grant Nos.11690023,11373014,and 11633001)the Beijing Talents Fund of Organization Department of Beijing Municipal Committee of the CPC,and the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB23000000).
文摘It is well known that the quantum fluctuation of entanglement(QFE) between Unruh–De Witt detector(modeled by a two-level atom) is always investigated in a relativistic setting. However, both of the Unruh radiation and quantum fluctuation effects play an important role in precise measurements of quantum entanglement. In this paper, we have quantitatively analyzed how the relativistic motion affects the QFE for two entangled Unruh–De Witt detectors, one of which is accelerated and interacting with the neighbor external scalar field. Our results show that the QFE, which initially increases by the Unruh thermal noise, will suddenly decay when the acceleration reaches to a considerably large value. Therefore, the relativistic effect will lead to non-negligible QFE effect. We also find that the initial QFE(without acceleration effect) reaches its minimum value at the maximally entangled state and the separable state. More importantly, our analysis demonstrates that although the QFE has a huge decay when the acceleration is greater than ~ 0.96, the ratio of △E/C is still very large, due to the simultaneous decay of concurrence to a very low value. Finally, enlightened by the well-known equivalence principle,we discuss the possibility of applying the above findings to the dynamics of QFE under the influence of gravitation field.
文摘<p align="justify"> <span style="font-family:Verdana;">In this note, we propose that an object moving with proper constant acceleration, i.e., a Rindler observer experiences a sublimation (or evaporation) process. In this first proposal, we do not consider the backreaction due to the sublimation. We focus on charged matter particles for the discussion, but for simplicity, we present the quantization of the neutrally charged massive scalar field in Rindler space. The amplitude from the Minkowski observer perspective of detection of matter particles that have been emitted by a Rindler observer, or accelerated detector, is computed in a new fashion. We make a comparison between the Rindler observer sublimation and the black hole evaporation. We present three variants of a new experimental setup, and we show that in two of them, the Minkowski amplitude of detection of matter particles corresponds to that of a thermal process. There is one, however, where deviations from thermality can be found. It is numerically explored.</span> </p>
基金supported by the Key Program of the National Natural Science Foundation of China(Grant Nos.12035005,and 12065016)the Young Elite Scientist Sponsorship Program by Guizhou Science and Technology Association(Grant No.GASTYESS202424)+3 种基金the Discipline-Team of Liupanshui Normal University of China(Grant No.LPSSY2023XKTD11)the Guizhou Provincial Department of Education Higher Education Science Research Project for Youth Project(Grant Nos.Qian Jiao Ji[2022]345,and Qian Jiao Ji[2022]346)the Scientific Research Start-Up Funds of Hangzhou Normal University(Grant No.4245C50224204016)Hangzhou Leading Youth Innovation and Entrepreneurship Team Project(Grant No.TD2024005)。
文摘In the framework of open quantum systems,we study the dynamics of an accelerated quantum battery(QB),modeled as an Unruh-DeWitt detector interacting with a real massless scalar quantum field.The QB is driven by an external classical force acting as a charger.A major challenge in this setup is the environment-induced decoherence,which leads to energy dissipation of the QB.Accelerated motion exacerbates this dissipation,manifesting effects analogous to those experienced by a static QB in a thermal bath in free space,consistent with the Unruh effect.To overcome these challenges,we introduce a reflecting boundary in a space,which modifies the vacuum fluctuations of the field and leads to a position-dependent suppression of dissipation for the Unruh-DeWitt QB.Our analysis reveals that as the QB approaches the boundary,the relevant dissipation is significantly reduced.In particular,when the QB is placed extremely close to the boundary,the dissipation is nearly eliminated,as if the QB were a closed system.Furthermore,we identify a characteristic length scale associated with the acceleration of QB.When the distance between the QB and the boundary is much smaller than this scale,the boundary effectively suppresses dissipation,and this suppression effect becomes identical for both an accelerated QB and a static QB in a thermal bath.Conversely,when the distance is beyond this scale,the suppression effect weakens and manifests a significant difference between these two cases.Our findings demonstrate the potential of boundary-induced modifications in vacuum fluctuations to effectively suppress dissipation,offering valuable insights for optimizing QB performance.This work paves the way for the development of high-efficiency quantum energy storage systems in the relativistic framework.
基金Supported by the National Natural Science Foundation of China under Grant No.11305058the Doctoral Scientific Fund Project of the Ministry of Education of China under Grant No.20134306120003
文摘The fluctuation and relative fluctuation of entanglement entropy of a bipartite system for Dirac fields in noninertial frames are investigated. It is shown that the fluctuation and relative fluctuation of entanglement entropy are observer-dependent, which depend on their observed frames. It is found that both the fluctuation and relative fluctuation of entanglement entropy become more noticeable with the increasing of the subsystem's acceleration. We also find that the entanglement entropy always has fluctuation regardless of the initial state parameter and for any magnitude of the acceleration. We argue that the statistical mean for the measurement of entanglement entropy relates to the accelerated motion of the observer.
文摘The restoration of spontaneous symmetry breaking for a scalar field theory for an accelerated observer is discussed by the one-loop effective potential calculation and by considering the effective potential for composite operators. Above a critical acceleration, corresponding to the critical restoration temperature, Tc, for a Minkowski observer by Unruh relation, i.e. ac/2π=Tc, the symmetry is restored. This result confirms other recent calculations in effective field theories that symmetry restoration can occur for an observer with an acceleration larger than some critical value. From the physical point of view, a constant acceleration mimics a gravitational field and the critical acceleration to restore the spontaneous symmetry breaking corresponds to a huge gravitational effect which prevents boson condensation.
