We introduce a new kind of four-mode continuous variable entangled state in Fock space. The completeness relation and the partly nonorthonormal property of such a state are proven. The scheme to generate this state is...We introduce a new kind of four-mode continuous variable entangled state in Fock space. The completeness relation and the partly nonorthonormal property of such a state are proven. The scheme to generate this state is presented by combining a symmetrical beamsplitter, a parametric down-conversion and a polarizer. After making a single-mode quadrature amplitude measurement, the remaining three modes are kept in entanglement. And its applications are also discussed.展开更多
By virtue of the technique of integration within an ordered product of operators a new four-mode squeezing operator that squeezes the four-mode quadrature operators of light field in the standard way is found. This op...By virtue of the technique of integration within an ordered product of operators a new four-mode squeezing operator that squeezes the four-mode quadrature operators of light field in the standard way is found. This operator differs from the direct product of two two-mode squeezing operators, It is the exponential operator V≡exp[ir （Q1P2＋Q2P3＋Q3P4＋Q4P1）].The Wigner function of the new four-mode squeezed state is ealculated,which quite differs from that of the direct-product state of two usual two-mode squeezed states.展开更多
Stationary entanglement in a four-mode optomechanical system,especially under room-temperature,is discussed.In this scheme,when the coupling strengths between the two target modes and the mechanical resonator are equa...Stationary entanglement in a four-mode optomechanical system,especially under room-temperature,is discussed.In this scheme,when the coupling strengths between the two target modes and the mechanical resonator are equal,the results cannot be explained by the Bogoliubov-mode-based scheme.This is related to the idea of quantummechanics-free subspace,which plays an important role when the thermal noise of the mechanical modes is considered.Significantly prominent steady-state entanglement can be available under room-temperature.展开更多
Based on a silicon platform, we design and fabricate a four-mode division(de)multiplexer for chip-scale optical data transmission in the 2 μm waveband for the first time, to the best of our knowledge. The(de)multiple...Based on a silicon platform, we design and fabricate a four-mode division(de)multiplexer for chip-scale optical data transmission in the 2 μm waveband for the first time, to the best of our knowledge. The(de)multiplexer is composed of three tapered directional couplers for both mode multiplexing and demultiplexing processes. In the experiment, the average crosstalk for four channels is measured to be less than-18 dB over a wide wavelength range(70 nm) from 1950 to 2020 nm, and the insertion losses are also assessed. Moreover, we further demonstrate stable 5 Gbit/s direct modulation data transmission through the fabricated silicon photonic devices with nonreturn-to-zero on–off keying signals. The experimental results show clear eye diagrams, and the penalties at a bit error rate of 3.8 × 10-3 are all less than 2.5 dB after on-chip data transmission. The obtained results indicate that the presented silicon four-mode division multiplexer in the mid-infrared wavelength band might be a promising candidate facilitating chip-scale high-speed optical interconnects.展开更多
为了破解我国公共卫生硕士(master of public health,MPH)培养中理论与实践脱节、人才培养与行业需求错位的难题,杭州医学院与浙江省疾病预防控制中心开展联合办学实践,探索实战型MPH培养模式的发展路径。通过创新“双主体、双导师”协...为了破解我国公共卫生硕士(master of public health,MPH)培养中理论与实践脱节、人才培养与行业需求错位的难题,杭州医学院与浙江省疾病预防控制中心开展联合办学实践,探索实战型MPH培养模式的发展路径。通过创新“双主体、双导师”协同育人机制,确立需求导向的培养目标,构建应用导向的课程体系,打造“1+11”疾控实践平台,建立“能力本位”多元评价与“四证合一”认证体系,形成了“理论-实践-认证”一体化培养模式。本研究结果表明,参与一体化培养模式实践探索的MPH研究生核心实战能力显著提升,硕士学位论文源于疾控实际工作比例超过50%,高校与疾控机构实现了资源互补与双赢发展。同时,本研究还提出了完善联合培养机制、优化实践导师激励、推进实践基地同质化建设等建议,以持续深化MPH培养模式改革。MPH培养模式实践探索为我国公共卫生专业学位教育改革提供了可资借鉴的实施路径。展开更多
基金supported by the Natural Science Foundation of Jiangxi Province,China (Grant No 2007GZW0171)the Foundation of Education Department of Jiangxi Province,China (Grant No [2007] 136)
文摘We introduce a new kind of four-mode continuous variable entangled state in Fock space. The completeness relation and the partly nonorthonormal property of such a state are proven. The scheme to generate this state is presented by combining a symmetrical beamsplitter, a parametric down-conversion and a polarizer. After making a single-mode quadrature amplitude measurement, the remaining three modes are kept in entanglement. And its applications are also discussed.
基金The project supported by the President Foundation of the Chinese Academy of Sciences and National Natural Science Foundation of China under Grant No. 10475657
文摘By virtue of the technique of integration within an ordered product of operators a new four-mode squeezing operator that squeezes the four-mode quadrature operators of light field in the standard way is found. This operator differs from the direct product of two two-mode squeezing operators, It is the exponential operator V≡exp[ir （Q1P2＋Q2P3＋Q3P4＋Q4P1）].The Wigner function of the new four-mode squeezed state is ealculated,which quite differs from that of the direct-product state of two usual two-mode squeezed states.
基金Supported by National Natural Science Foundation of China under Grant No.11174109
文摘Stationary entanglement in a four-mode optomechanical system,especially under room-temperature,is discussed.In this scheme,when the coupling strengths between the two target modes and the mechanical resonator are equal,the results cannot be explained by the Bogoliubov-mode-based scheme.This is related to the idea of quantummechanics-free subspace,which plays an important role when the thermal noise of the mechanical modes is considered.Significantly prominent steady-state entanglement can be available under room-temperature.
基金National Natural Science Foundation of China(NSFC)(61761130082,11574001,11774116,61705072)Royal Society-Newton Advanced Fellowship+4 种基金National Program for Support of Top-notch Young ProfessionalsNatural Science Foundation of Hubei Province(2018CFA048,ZRMS2017000413)Beijing University of Posts and Telecommunications(BUPT))(IPOC2018A002)Program for HUST Academic Frontier Youth Team(2016QYTD05)Fundamental Research Funds for the Central Universities(2019kfyRCPY037)
文摘Based on a silicon platform, we design and fabricate a four-mode division(de)multiplexer for chip-scale optical data transmission in the 2 μm waveband for the first time, to the best of our knowledge. The(de)multiplexer is composed of three tapered directional couplers for both mode multiplexing and demultiplexing processes. In the experiment, the average crosstalk for four channels is measured to be less than-18 dB over a wide wavelength range(70 nm) from 1950 to 2020 nm, and the insertion losses are also assessed. Moreover, we further demonstrate stable 5 Gbit/s direct modulation data transmission through the fabricated silicon photonic devices with nonreturn-to-zero on–off keying signals. The experimental results show clear eye diagrams, and the penalties at a bit error rate of 3.8 × 10-3 are all less than 2.5 dB after on-chip data transmission. The obtained results indicate that the presented silicon four-mode division multiplexer in the mid-infrared wavelength band might be a promising candidate facilitating chip-scale high-speed optical interconnects.
文摘为了破解我国公共卫生硕士(master of public health,MPH)培养中理论与实践脱节、人才培养与行业需求错位的难题,杭州医学院与浙江省疾病预防控制中心开展联合办学实践,探索实战型MPH培养模式的发展路径。通过创新“双主体、双导师”协同育人机制,确立需求导向的培养目标,构建应用导向的课程体系,打造“1+11”疾控实践平台,建立“能力本位”多元评价与“四证合一”认证体系,形成了“理论-实践-认证”一体化培养模式。本研究结果表明,参与一体化培养模式实践探索的MPH研究生核心实战能力显著提升,硕士学位论文源于疾控实际工作比例超过50%,高校与疾控机构实现了资源互补与双赢发展。同时,本研究还提出了完善联合培养机制、优化实践导师激励、推进实践基地同质化建设等建议,以持续深化MPH培养模式改革。MPH培养模式实践探索为我国公共卫生专业学位教育改革提供了可资借鉴的实施路径。
