TL81 2001031561合肥光源测量束团纵向精细结构的单光子计数系统设计=Design of single photon counting system for measuring the longitudinal bunch structurein HLS[刊,中]/孙葆根,何多慧(中国科技大学国家同步辐射实验室.安徽,合...TL81 2001031561合肥光源测量束团纵向精细结构的单光子计数系统设计=Design of single photon counting system for measuring the longitudinal bunch structurein HLS[刊,中]/孙葆根,何多慧(中国科技大学国家同步辐射实验室.安徽,合肥(230029))∥光子学报.-展开更多
We present two nonlocal entanglement concentration protocols(ECPs)to distill a subset of N-photon systems in a GreenbergerHorne-Zeilinger(GHZ)state or a W state from a set of photon systems in a partially entangled GH...We present two nonlocal entanglement concentration protocols(ECPs)to distill a subset of N-photon systems in a GreenbergerHorne-Zeilinger(GHZ)state or a W state from a set of photon systems in a partially entangled GHZ-like pure state or a lessentangled W-like state with known parameters,respectively.Our ECPs have some advantages.First,our ECPs work in a heralded way with linear-optical elements only,without the postselection based on nonlinear optics,far different from the previous ECPs.Second,they require only a copy of the less-entangled photon system in each round of the entanglement concentration process,not two copies,which decreases the difficulty of their implementation in experiment largely.Third,our ECPs avoid checking the photon number in the output modes of linear-optical elements with the sophisticated single-photon detectors.Moreover,all parties can operate the process for concentration simultaneously and independently,which leads to flexible operations and improves the performance greatly in experiment.These advantages make our ECPs useful in practical applications in long-distance quantum communication network.展开更多
Exploiting the optical excitation selection rules in graphene quantum dots, we investigate theoretically the entanglement generation process and entanglement concentration process of valley qubits. Our protocol shows ...Exploiting the optical excitation selection rules in graphene quantum dots, we investigate theoretically the entanglement generation process and entanglement concentration process of valley qubits. Our protocol shows that the graphene-based quantum dots can be distributed in a maximally entangled state through the interaction with single photons. In our proposed scheme, the setups are simplified as only single-photon detection is required. This provides a fast, all-optical manipulation of on-chip qubits,which gives an effective way for quantum information processing in graphene-based solid qubits.展开更多
The capability to image, as well as control and manipulate single molecules such as nucleic acids(DNA or RNA) can greatly enrich our knowledge of the roles of individual biomolecules in cellular processes and their be...The capability to image, as well as control and manipulate single molecules such as nucleic acids(DNA or RNA) can greatly enrich our knowledge of the roles of individual biomolecules in cellular processes and their behavior in native environments. Here we summarize the recent advances of single nucleic acid imaging based on optical observation and force manipulation. We start by discussing the superiority of single molecule image, the central roles nucleic acids play in biosystems, and the significance of single molecule image towards nucleic acids. We then list a series of representative examples in brief to illustrate how nucleic acid of various morphologies has been imaged from different aspects, and what can be learned from such characterizations. Finally,concluding remarks on parts of which should be improved and outlook are outlined.展开更多
Photochemical and thermal isomerization of various azobenzenes was systematically investigated to understand the correlation between the molecular structure and trans → cis isomerization characteristics of azobenzene...Photochemical and thermal isomerization of various azobenzenes was systematically investigated to understand the correlation between the molecular structure and trans → cis isomerization characteristics of azobenzenes. A blue shift in π-π absorption band of ortho-alkylated azobenzenes （1o and 2o） was observed together with a reduction in molar extinction coefficient （e） in comparison with both meta-alkylated azobenzenes （4m and 5m） and 7p lacking the meta and ortho substituents. For orthoalkylated azobenzene, photochemical trans-to-cis isomerization and thermal back cis-to-trans isomerization in solution oc- curred slowly when compared with 4m, 5m and 7p. The half-life time of the cis form of 20 was found to be 380 h, which is about 8-50 times longer than those of comparable 4m, 5m （43-13 h） and 7p （7 h）. Furthermore, comparison of the molecular structure and isomerization characteristics of azobenzene thiol （20 and 5m） self-assembled monolayers on flat gold surfaces indicates that the trans-to-cis photoconversion in monolayer systems is influenced by steric hindrance and strong intermoleculax interaction between azobenzene units.展开更多
文摘TL81 2001031561合肥光源测量束团纵向精细结构的单光子计数系统设计=Design of single photon counting system for measuring the longitudinal bunch structurein HLS[刊,中]/孙葆根,何多慧(中国科技大学国家同步辐射实验室.安徽,合肥(230029))∥光子学报.-
基金supported by the National Natural Science Foundation of China(Grant Nos.11174039 and 11474026)the Program for New Century Excellent Talents in University(Grant No.NECT-11-0031)the Open Foundation of State Key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications)(Grant No.SKLNST-2013-1-13)
文摘We present two nonlocal entanglement concentration protocols(ECPs)to distill a subset of N-photon systems in a GreenbergerHorne-Zeilinger(GHZ)state or a W state from a set of photon systems in a partially entangled GHZ-like pure state or a lessentangled W-like state with known parameters,respectively.Our ECPs have some advantages.First,our ECPs work in a heralded way with linear-optical elements only,without the postselection based on nonlinear optics,far different from the previous ECPs.Second,they require only a copy of the less-entangled photon system in each round of the entanglement concentration process,not two copies,which decreases the difficulty of their implementation in experiment largely.Third,our ECPs avoid checking the photon number in the output modes of linear-optical elements with the sophisticated single-photon detectors.Moreover,all parties can operate the process for concentration simultaneously and independently,which leads to flexible operations and improves the performance greatly in experiment.These advantages make our ECPs useful in practical applications in long-distance quantum communication network.
基金supported by the National Natural Science Foundation of China(1140403161205117+3 种基金and61471050)Beijing Higher Education Young Elite Teacher Project(YETP0456)the Fundamental Research Funds for the Central Universities(2014RC0903)the State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)
文摘Exploiting the optical excitation selection rules in graphene quantum dots, we investigate theoretically the entanglement generation process and entanglement concentration process of valley qubits. Our protocol shows that the graphene-based quantum dots can be distributed in a maximally entangled state through the interaction with single photons. In our proposed scheme, the setups are simplified as only single-photon detection is required. This provides a fast, all-optical manipulation of on-chip qubits,which gives an effective way for quantum information processing in graphene-based solid qubits.
基金supported by the National Natural Science Foundation of China (21525523, 21574048, 21375042, 21405054)the National Basic Research Program of China (2015CB932600, 2013CB933000)+1 种基金the Special Fund for Strategic New Industry Development of Shenzhen, China (JCYJ20150616144425376)1000 Young Talent (to Fan Xia)
文摘The capability to image, as well as control and manipulate single molecules such as nucleic acids(DNA or RNA) can greatly enrich our knowledge of the roles of individual biomolecules in cellular processes and their behavior in native environments. Here we summarize the recent advances of single nucleic acid imaging based on optical observation and force manipulation. We start by discussing the superiority of single molecule image, the central roles nucleic acids play in biosystems, and the significance of single molecule image towards nucleic acids. We then list a series of representative examples in brief to illustrate how nucleic acid of various morphologies has been imaged from different aspects, and what can be learned from such characterizations. Finally,concluding remarks on parts of which should be improved and outlook are outlined.
基金supported by the Global COE Program from the Ministry of Education,Culture,Sports,Science,and Technology of Japanese Government
文摘Photochemical and thermal isomerization of various azobenzenes was systematically investigated to understand the correlation between the molecular structure and trans → cis isomerization characteristics of azobenzenes. A blue shift in π-π absorption band of ortho-alkylated azobenzenes （1o and 2o） was observed together with a reduction in molar extinction coefficient （e） in comparison with both meta-alkylated azobenzenes （4m and 5m） and 7p lacking the meta and ortho substituents. For orthoalkylated azobenzene, photochemical trans-to-cis isomerization and thermal back cis-to-trans isomerization in solution oc- curred slowly when compared with 4m, 5m and 7p. The half-life time of the cis form of 20 was found to be 380 h, which is about 8-50 times longer than those of comparable 4m, 5m （43-13 h） and 7p （7 h）. Furthermore, comparison of the molecular structure and isomerization characteristics of azobenzene thiol （20 and 5m） self-assembled monolayers on flat gold surfaces indicates that the trans-to-cis photoconversion in monolayer systems is influenced by steric hindrance and strong intermoleculax interaction between azobenzene units.
