DSM(SVM) is a memory model which was proposed at the 1980s'. DSM solved the problem thatscalability was contradict with easy programming and merge their merits. The efficiency of DSM is still aproblem. The propose...DSM(SVM) is a memory model which was proposed at the 1980s'. DSM solved the problem thatscalability was contradict with easy programming and merge their merits. The efficiency of DSM is still aproblem. The proposed solutions include prefetching and adopting new coherence model, but neither ofthem is a perfect solution. Prefetch will be less efficient when there are too many false sharing. The weak, relaxed coherence model is quite different from sequential coherence which was assumed by mostprogrammers intuitively, so programming and debugging becomes very difficult. We have proposed StrictWeak Hybrid Coherence (SWHC) model which can eliminate false sharing and provide more temporal andspatial locality, we also provide a scheme to keep sequential coherent. But SWHC model is complicate, asimplified model for Pthread share memory parallel computing model is proposed in the paper.展开更多
Recently, the Hong-Ou-Mandel （HOM） interference between two independent weak coherent pulses （WCPs） has been paid much attention due to the measurement-device-independent （MDI） quantum key distribution （QKD）. ...Recently, the Hong-Ou-Mandel （HOM） interference between two independent weak coherent pulses （WCPs） has been paid much attention due to the measurement-device-independent （MDI） quantum key distribution （QKD）. Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is 〈 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection.展开更多
Passive decoy-state quantum key distribution systems, proven to be more desirable than active ones in some scenarios, also have the problem of device imperfections like finite-length keys. In this paper, based on the ...Passive decoy-state quantum key distribution systems, proven to be more desirable than active ones in some scenarios, also have the problem of device imperfections like finite-length keys. In this paper, based on the WCP source which can be used for the passive decoy-state method, we obtain the expressions of single-photon error rates, single-photon counts, and phase error rates. According to the information of smooth min-entropy, we calculate the key generation rate under the condition of finite-length key. Key generation rates with different numbers of pulses are compared by numerical simulations. From the results, it can be seen that the passive decoy-state method can have good results if the total number of pulses reaches 1010. We also simulate the passive decoy-state method with different probabilities of choosing a pulse for parameter estimation when the number of pulses is fixed.展开更多
Passive decoy-state quantum key distribution is more desirable than the active one in some scenarios. It is also affected by the imperfections of the devices. In this paper, the influence of modulator attenuation on t...Passive decoy-state quantum key distribution is more desirable than the active one in some scenarios. It is also affected by the imperfections of the devices. In this paper, the influence of modulator attenuation on the passive decoy-state method is considered. We introduce and analyze the unbalanced Mach-Zehnder interferometer, briefly, and combining with the virtual source and imaginary unitary transformation, we characterize the passive decoy-state method using a weak coherent photon source with modulator attenuation. According to the attenuation parameter 6, the pass efficiencies are given. Then, the key generation rate can be acquired. From numerical simulations, it can be seen that modulator attenuation has a non- negligible influence on the performance of passive-state QKD protocol. Based on the research, the analysis method of virtual source and imaginary unitary transformation are preferred in analyzing passive decoy state protocol, and the passive decoy-state method is better than the active one and is close to the active vacuum ＋ weak decoy state under the condition of having the same modulator attenuation.展开更多
This paper presents a method for generating entanglement molecules, which is introduced by Dur （2001 Phys. Rev. A）. In this scheme, N ladder-type three-level atoms are sent through a resonant weak coherent cavity fi...This paper presents a method for generating entanglement molecules, which is introduced by Dur （2001 Phys. Rev. A）. In this scheme, N ladder-type three-level atoms are sent through a resonant weak coherent cavity field, then the system states are measured. And the system field may collapse onto some possible types of entanglement molecules. Meanwhile it discusses about the interaction time from the experimental point of view, and compare the result with the previous scheme proposed by Huang （2004 J. Phys. B： At. Mol. Opt. Phys.）.展开更多
With the widespread application of quantum communication technology,there is an urgent need to enhance unconditionally secure key rates and capacity.Measurement-device-independent quantum key distribution(MDI-QKD),pro...With the widespread application of quantum communication technology,there is an urgent need to enhance unconditionally secure key rates and capacity.Measurement-device-independent quantum key distribution(MDI-QKD),proven to be immune to detection-side channel attacks,is a secure and reliable quantum communication scheme.The core of this scheme is Hong–Ou–Mandle(HOM)interference,a quantum optical phenomenon with no classical analog,where identical photons meeting on a symmetric beam splitter(BS)undergo interference and bunching.Any differences in the degrees of freedom(frequency,arrival time,spectrum,polarization,and the average number of photons per pulse)between the photons will deteriorate the interference visibility.Here,we demonstrate 16-channel weak coherent pulses(WCPs)of HOM interference with all channels’interference visibility over 46%based on two independent frequency-post-aligned soliton microcombs(SMCs).In our experiment,full locking and frequency alignment of the comb teeth between the two SMCs were achieved through pump frequency stabilization,SMC repetition rate locking,and fine tuning of the repetition rate.This demonstrates the feasibility of using independently generated SMCs as multi-wavelength sources for quantum communication.Meanwhile,SMC can achieve hundreds of frequency-stable comb teeth by locking only two parameters,which further reduces the complexity of frequency locking and the need for finding sufficient suitable frequency references compared to independent laser arrays.展开更多
Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering,such as legal documentation and digital intellectual property protection.Classical timestamp protocol...Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering,such as legal documentation and digital intellectual property protection.Classical timestamp protocols rely on computational assumptions for security,rendering them vulnerable to quantum attacks,which is a critical limitation given the rapid progress in quantum computing.To address this,we propose an information-theoretically secure quantum timestamping protocol based on one-time universal hashing with quantum keys.Our protocol simultaneously achieves information-theoretic security and high efficiency,enabling secure timestamping for arbitrarily long documents.Simulations demonstrate a generation rate exceeding 100 timestamps per second over intercity distances.In addition,our protocol only requires weak coherent states,making it practical for large-scale deployment.This work advances the field of quantum timestamping and contributes to the broader development of quantum cryptography and the future quantum internet.展开更多
The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows th...The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows that multiphoton pulses have posed a serious threat to the participant’s privacy in QPQ protocols.Then we propose a decoy-state method that can help the honest participant detect the attack by exploiting multiphoton pulses and improving the key distillation process to defend against such attack.The analysis demonstrates that our decoy-state method significantly improves the security of the QPQ with weak coherent pulses,which solves a major obstacle in the practical application of the QPQ.展开更多
文摘DSM(SVM) is a memory model which was proposed at the 1980s'. DSM solved the problem thatscalability was contradict with easy programming and merge their merits. The efficiency of DSM is still aproblem. The proposed solutions include prefetching and adopting new coherence model, but neither ofthem is a perfect solution. Prefetch will be less efficient when there are too many false sharing. The weak, relaxed coherence model is quite different from sequential coherence which was assumed by mostprogrammers intuitively, so programming and debugging becomes very difficult. We have proposed StrictWeak Hybrid Coherence (SWHC) model which can eliminate false sharing and provide more temporal andspatial locality, we also provide a scheme to keep sequential coherent. But SWHC model is complicate, asimplified model for Pthread share memory parallel computing model is proposed in the paper.
基金Project supported by the National Basic Research Program of China(Grants Nos.2011CBA00200 and 2011CB921200)the National Natural Science Foundation of China(Grant Nos.61201239,61205118,11304397,and 61475148)the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB01030100 and XDB01030300)
文摘Recently, the Hong-Ou-Mandel （HOM） interference between two independent weak coherent pulses （WCPs） has been paid much attention due to the measurement-device-independent （MDI） quantum key distribution （QKD）. Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is 〈 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection.
基金supported by the National Natural Science Foundation of China(Grant No.11304397)
文摘Passive decoy-state quantum key distribution systems, proven to be more desirable than active ones in some scenarios, also have the problem of device imperfections like finite-length keys. In this paper, based on the WCP source which can be used for the passive decoy-state method, we obtain the expressions of single-photon error rates, single-photon counts, and phase error rates. According to the information of smooth min-entropy, we calculate the key generation rate under the condition of finite-length key. Key generation rates with different numbers of pulses are compared by numerical simulations. From the results, it can be seen that the passive decoy-state method can have good results if the total number of pulses reaches 1010. We also simulate the passive decoy-state method with different probabilities of choosing a pulse for parameter estimation when the number of pulses is fixed.
基金supported by the National Natural Science Foundation of China(Grant No.11304397)
文摘Passive decoy-state quantum key distribution is more desirable than the active one in some scenarios. It is also affected by the imperfections of the devices. In this paper, the influence of modulator attenuation on the passive decoy-state method is considered. We introduce and analyze the unbalanced Mach-Zehnder interferometer, briefly, and combining with the virtual source and imaginary unitary transformation, we characterize the passive decoy-state method using a weak coherent photon source with modulator attenuation. According to the attenuation parameter 6, the pass efficiencies are given. Then, the key generation rate can be acquired. From numerical simulations, it can be seen that modulator attenuation has a non- negligible influence on the performance of passive-state QKD protocol. Based on the research, the analysis method of virtual source and imaginary unitary transformation are preferred in analyzing passive decoy state protocol, and the passive decoy-state method is better than the active one and is close to the active vacuum ＋ weak decoy state under the condition of having the same modulator attenuation.
基金supported by the Natural Science Foundation of Fujian Province of China (Grant No T0650007)Funds from Education Department of Fujian Province of China (Grant No JB06041)
文摘This paper presents a method for generating entanglement molecules, which is introduced by Dur （2001 Phys. Rev. A）. In this scheme, N ladder-type three-level atoms are sent through a resonant weak coherent cavity field, then the system states are measured. And the system field may collapse onto some possible types of entanglement molecules. Meanwhile it discusses about the interaction time from the experimental point of view, and compare the result with the previous scheme proposed by Huang （2004 J. Phys. B： At. Mol. Opt. Phys.）.
基金Innovation Program for Quantum Science and Technology(2021ZD0300701,2021ZD0301500)CAS Project for Young Scientists in Basic Research(YSBR-069)+1 种基金National Natural Science Foundation of China(62075238,62205036)National Key Research and Development Program of China(2021YFB2800603)。
文摘With the widespread application of quantum communication technology,there is an urgent need to enhance unconditionally secure key rates and capacity.Measurement-device-independent quantum key distribution(MDI-QKD),proven to be immune to detection-side channel attacks,is a secure and reliable quantum communication scheme.The core of this scheme is Hong–Ou–Mandle(HOM)interference,a quantum optical phenomenon with no classical analog,where identical photons meeting on a symmetric beam splitter(BS)undergo interference and bunching.Any differences in the degrees of freedom(frequency,arrival time,spectrum,polarization,and the average number of photons per pulse)between the photons will deteriorate the interference visibility.Here,we demonstrate 16-channel weak coherent pulses(WCPs)of HOM interference with all channels’interference visibility over 46%based on two independent frequency-post-aligned soliton microcombs(SMCs).In our experiment,full locking and frequency alignment of the comb teeth between the two SMCs were achieved through pump frequency stabilization,SMC repetition rate locking,and fine tuning of the repetition rate.This demonstrates the feasibility of using independently generated SMCs as multi-wavelength sources for quantum communication.Meanwhile,SMC can achieve hundreds of frequency-stable comb teeth by locking only two parameters,which further reduces the complexity of frequency locking and the need for finding sufficient suitable frequency references compared to independent laser arrays.
基金supported by the National Natural Science Foundation of China(Grant No.12274223)the Program for Innovative Talents,Entrepreneurs in Jiangsu(Grant No.JSSCRC2021484)the Key Research and Development Program of Nanjing Jiangbei New Area(Grant No.ZDYD20210101)。
文摘Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering,such as legal documentation and digital intellectual property protection.Classical timestamp protocols rely on computational assumptions for security,rendering them vulnerable to quantum attacks,which is a critical limitation given the rapid progress in quantum computing.To address this,we propose an information-theoretically secure quantum timestamping protocol based on one-time universal hashing with quantum keys.Our protocol simultaneously achieves information-theoretic security and high efficiency,enabling secure timestamping for arbitrarily long documents.Simulations demonstrate a generation rate exceeding 100 timestamps per second over intercity distances.In addition,our protocol only requires weak coherent states,making it practical for large-scale deployment.This work advances the field of quantum timestamping and contributes to the broader development of quantum cryptography and the future quantum internet.
基金supported by the National Natural Science Foundation of China(Grant Nos.62171418,U19A2076,61901425,and 61702061)Natural Science Foundation of Chongqing(Grant No.cstc2020jcyjmsxm X0719)+2 种基金National Science Key Lab Fund Project(Grant No.6142103200105)Fundamental Research Funds for the Central Universities(Grant Nos.2020CDJQY-A018,and 2020CDJ-LHZZ-056)Sichuan Science and Technology Program(Grant No.019JDJQ0060)。
文摘The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows that multiphoton pulses have posed a serious threat to the participant’s privacy in QPQ protocols.Then we propose a decoy-state method that can help the honest participant detect the attack by exploiting multiphoton pulses and improving the key distillation process to defend against such attack.The analysis demonstrates that our decoy-state method significantly improves the security of the QPQ with weak coherent pulses,which solves a major obstacle in the practical application of the QPQ.
