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
The retrieval of lost entanglement for relatively accelerated fermionic observers of a tripartite system by a partial measurement technique has been investigated.From the prospective of the negativities of one-tangles...The retrieval of lost entanglement for relatively accelerated fermionic observers of a tripartite system by a partial measurement technique has been investigated.From the prospective of the negativities of one-tangles and theπ-tangle,we show that the degraded entanglement in noninertial frames with single-mode approximation is completely retrieved by an optimal strength of the partial measurement or the partial measurement reversal.In addition,we find that the optimal one-tangle with respect to inertial and noninertial observers turns out to be the same for an optimal strength of partial measurements at q0=0 when two accelerated observers move with infinite acceleration.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
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
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
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
We studied the quantum correlations of a three-body Unruh-DeWitt detector system using genuine tripartite entanglement(GTE)and geometric quantum discord(GQD).We considered two representative three-body initial entangl...We studied the quantum correlations of a three-body Unruh-DeWitt detector system using genuine tripartite entanglement(GTE)and geometric quantum discord(GQD).We considered two representative three-body initial entangled states,namely the GHZ state and the W state.We demonstrated that the quantum correlations of the tripartite system are completely destroyed at the limit of infinite acceleration.In particular,it is found that the GQD of the two initial states exhibits“sudden change”behavior with increasing acceleration.It is shown that the quantum correlations of the W state are more sensitive than those of the GHZ state under the effect of Unruh thermal noise.The GQD is a more robust quantum resource than the GTE,and we can achieve robustness in discord-type quantum correlations by selecting the smaller energy gap in the detector.These findings provide guidance for selecting appropriate quantum states and resources for quantum information processing tasks in a relativistic setting.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
Verlinde＇s recent work, which shows that gravity may be explained as an entropic force caused by the changes in information associated with the positions of material bodies, is extended to study the Unruh-Verlinde te...Verlinde＇s recent work, which shows that gravity may be explained as an entropic force caused by the changes in information associated with the positions of material bodies, is extended to study the Unruh-Verlinde temperature and energy of a static spherically symmetric charged black hole. The results indicate that the Unruh-Verlinde temperature is equal to the Hawking temperature at the event horizon. The energy is dependent on the radius of the screen, which is Mso a consequence of the Gauss＇ laws of gravity and electrostatics.展开更多
We introduce an ultra high energy combined KAM-Rindler fractal spacetime quantum manifold, which increasingly resembles Einstein’s smooth relativity spacetime, with decreasing energy. That way we derive an effective ...We introduce an ultra high energy combined KAM-Rindler fractal spacetime quantum manifold, which increasingly resembles Einstein’s smooth relativity spacetime, with decreasing energy. That way we derive an effective quantum gravity energy-mass relation and compute a dark energy density in complete agreement with all cosmological measurements, specifically WMAP and type 1a supernova. In particular we find that ordinary measurable energy density is given by E1= mc2 /22 while the dark energy density of the vacuum is given by E2 = mc2 (21/22). The sum of both energies is equal to Einstein’s energy E = mc2. We conclude that E= mc2 makes no distinction between ordinary energy and dark energy. More generally we conclude that the geometry and topology of quantum entanglement create our classical spacetime and glue it together and conversely quantum entanglement is the logical consequence of KAM theorem and zero measure topology of quantum spacetime. Furthermore we show via our version of a Rindler hyperbolic spacetime that Hawking negative vacuum energy, Unruh temperature and dark energy are different sides of the same medal.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。
基金supported by the INTERWEAVE project,Erasmus Mundus Action 2 Strand 1 Lot 11,EACEA/42/11 Grant Agreement 2013-2538/001-001 EM Action 2 Partnership Asia-Europe,Fundacao da Ciência e Tecnologia and COMPETE 2020 program in FEDER component(EU),through the projects POCI-01-0145-FEDER-028887 and UID/FIS/04650/2013the support from the Fundacao da Ciência e Tecnologia(FCT)through a Doctoral Programme in the Physics and Mathematics of Information and the associated scholarship PD/BD/113651/2015 and through the grant UID/CTM/04540/2013+1 种基金the support of SQIG–Security and Quantum Information Group,under the Fundacao para a Ciência e a Tecnologia(FCT)project UID/EEA/50008/2019European funds,namely H2020 project SPARTA。
文摘The retrieval of lost entanglement for relatively accelerated fermionic observers of a tripartite system by a partial measurement technique has been investigated.From the prospective of the negativities of one-tangles and theπ-tangle,we show that the degraded entanglement in noninertial frames with single-mode approximation is completely retrieved by an optimal strength of the partial measurement or the partial measurement reversal.In addition,we find that the optimal one-tangle with respect to inertial and noninertial observers turns out to be the same for an optimal strength of partial measurements at q0=0 when two accelerated observers move with infinite acceleration.
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.
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(Grant Nos.12122504 and 12374408)the Natural Science Foundation of Hunan Province(Grant No.2023JJ30384).
文摘We studied the quantum correlations of a three-body Unruh-DeWitt detector system using genuine tripartite entanglement(GTE)and geometric quantum discord(GQD).We considered two representative three-body initial entangled states,namely the GHZ state and the W state.We demonstrated that the quantum correlations of the tripartite system are completely destroyed at the limit of infinite acceleration.In particular,it is found that the GQD of the two initial states exhibits“sudden change”behavior with increasing acceleration.It is shown that the quantum correlations of the W state are more sensitive than those of the GHZ state under the effect of Unruh thermal noise.The GQD is a more robust quantum resource than the GTE,and we can achieve robustness in discord-type quantum correlations by selecting the smaller energy gap in the detector.These findings provide guidance for selecting appropriate quantum states and resources for quantum information processing tasks in a relativistic setting.
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 Scientific and Technological Foundation of Chongqing Municipal Education Commission (KJ100706)
文摘Verlinde＇s recent work, which shows that gravity may be explained as an entropic force caused by the changes in information associated with the positions of material bodies, is extended to study the Unruh-Verlinde temperature and energy of a static spherically symmetric charged black hole. The results indicate that the Unruh-Verlinde temperature is equal to the Hawking temperature at the event horizon. The energy is dependent on the radius of the screen, which is Mso a consequence of the Gauss＇ laws of gravity and electrostatics.
文摘We introduce an ultra high energy combined KAM-Rindler fractal spacetime quantum manifold, which increasingly resembles Einstein’s smooth relativity spacetime, with decreasing energy. That way we derive an effective quantum gravity energy-mass relation and compute a dark energy density in complete agreement with all cosmological measurements, specifically WMAP and type 1a supernova. In particular we find that ordinary measurable energy density is given by E1= mc2 /22 while the dark energy density of the vacuum is given by E2 = mc2 (21/22). The sum of both energies is equal to Einstein’s energy E = mc2. We conclude that E= mc2 makes no distinction between ordinary energy and dark energy. More generally we conclude that the geometry and topology of quantum entanglement create our classical spacetime and glue it together and conversely quantum entanglement is the logical consequence of KAM theorem and zero measure topology of quantum spacetime. Furthermore we show via our version of a Rindler hyperbolic spacetime that Hawking negative vacuum energy, Unruh temperature and dark energy are different sides of the same medal.
