检索结果-南通市图书馆

Protecting geometric quantum discord via partially collapsing measurements of two qubits in multiple bosonic reservoirs

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2022年第4期31卷 163-169页

作者： Xue-Yun Bai Su-Ying Zhang Institute of Theoretical physics and State Key Laboratory of quantum optics and quantum optics Devices Shanxi UniversityTaiyuan 030006China

We study the dynamics of geometric quantum discord(GQD) between two qubits,each qubit interacting at the same time with K independent multiple bosonic reservoirs at zero *** both weak and strong qubit-reservoirs coupling regimes,we find that the increase of the number K of reservoirs can induce the damped oscillation of GQD,and enhance the memory effects of the overall *** the Hilbert-Schmidt norm GQD(two-norm GQD) is always smaller than the trace norm geometric quantum discord(one-norm GQD).Therefore,the one-norm GQD is a better way to measure the quantum ***,we propose an effective strategy to improve GQD by using partially collapsing measurements,and we find that the protection effect is better with the increase of the weak measurement strength.

关键词： geometric quantum discord(GQD) the Hilbert-Schmidt norm GQD the trace norm GQD partially collapsing measurements

Ultrafast optical modulation of the fluorescence from a single-photon emitter in silicon carbide

在线全文

学校读者我要写书评

暂无评论

photonics Research 2024年第5期12卷 941-946页

作者： MENGTING HE YUJING CAO JUNJIE LIN ZHIPING JU BOTAO WU E WU State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200241China photon Technology(Zhejiang)Co. Ltd.Jiaxing 314100China National Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200000China Department of physics and Shanghai Key Laboratory for Magnetic Resonance East China Normal UniversityShanghai 200241China Chongqing Key Laboratory of Precision optics Chongqing Institute of East China Normal UniversityChongqing 401120China Collaborative Innovation Center of Extreme optics Shanxi UniversityTaiyuan 030006China

The quest for the room-temperature optical transistor based on nonlinearities in single atoms or molecules is attracting a lot of *** this work,a single-photon emitter in cubic silicon carbide is verified that can operate as an optical switch at room temperature under pulsed green laser illumination with a near-infrared pulsed laser as the control *** demonstrated an ultrafast and reversible optical modulation with a high photoluminescence intensity suppression ratio up to 97.9%and a response time as short as 287.9±5.7 *** current development provides insights for high-precision and ultrafast optical switches,with possibilities for integration with emerging electronic installations to realize more intelligent photoelectric integrated devices.

关键词： emitter carbide photon

Engineering steady-state entanglement for two atoms held in separate cavities through laser cooling

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2014年第4期23卷 109-112页

作者：沈利托陈荣鑫吴怀志杨贞标 Laboratory of quantum optics Department of Physics Fuzhou University

We propose a scheme to prepare the steady-state entanglement for two atoms, which are held in separate cavities that are coupled through a short optical fiber or optical resonator. The entangled steady-state with a high fidelity can be achieved even with a low cooperativity parameter, by making use of the driving laser fields. Such a cooling mechanism is based on a resonant laser pump of the unwanted ground states to the excited states, which finally decay to the desired steady-state.

关键词： laser cooling steady-state entanglement optical fiber

Tunable two-axis spin model and spin squeezing in two cavities

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2016年第5期25卷 31-37页

作者：俞立先李彩凤樊景涛陈刚张天才贾锁堂 Department of physics Shaoxing University State Key Laboratory of quantum optics and quantum optics Devices Institute of Laser spectroscopy Shanxi University Institute of Theoretical physics Shanxi University Collaborative Innovation Center of Extreme optics Shanxi University State Key Laboratory of quantum optics and quantum optics Devices Institute of Opto-Electronics Shanxi University

Multi-mode cavities have now attracted much attention both experimentally and theoretically. In this paper, inspired by recent experiments of cavity-assisted Raman transitions, we realize a two-axis spin Hamiltonian H = q（J_x^2＋ χJ_y^2）＋ ω_0J_z in two cavities. This realized Hamiltonian has a distinct property that all parameters can be tuned independently. For proper parameters, the well-studied one- and two-axis twisting Hamiltonians are recovered, and the scaling of N^（-1） of the maximal squeezing factor can occur naturally. On the other hand, in the two-axis twisting Hamiltonian, spin squeezing is usually reduced when increasing the atomic resonant frequency ω_0. Surprisingly, we find that by combining with the dimensionless parameter χ（-1）, this atomic resonant frequency ω_0 can enhance spin squeezing greatly. These results are beneficial for achieving the required spin squeezing in experiments.

关键词： two-axis spin model spin squeezing two cavities

Current–phase relations of a ring-trapped Bose–Einstein condensate with a weak link

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2019年第1期28卷 218-222页

作者： Xiu-Rong Zhang Wei-Dong Li Institute of Theoretical physics and Department of physics State Key Laboratory of Quantum Optics and Quantum Optics DevicesCollaborative Innovation Center of Extreme OpticsShanxi UniversityTaiyuan 030006China

The current–phase relations of a ring-trapped Bose–Einstein condensate interrupted by a rotating rectangular barrier are extensively investigated with an analytical solution. A current–phase diagram, single and multi-valued relation, is presented with a rescaled barrier height and width. Our results show that the finite size makes the current–phase relation deviate a little bit from the cosine form for the soliton solution in the limit of a vanishing barrier, and the periodic boundary condition selects only the plane wave solution in the case of high barrier. The reason for multi-valued current–phase relation is given by investigating the behavior of soliton solution.

关键词： ring-trapped Bose–Einstein condensate weak link current–phase relation analytical solution

Polarization control of above-threshold ionization spectrum in elliptically polarized two-color laser fields

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第4期33卷 136-144页

作者：金发成杨慧慧宋晓红李飞杜玲玲薛红杰魏丽敏白悦刘浩翔王兵兵杨玮枫 Faculty of Science Xi'an Aeronautical InstituteXi'an 710077China School of physics and Optoelectronic Engineering Hainan UniversityHaikou 570288China Center for Theoretical physics Hainan UniversityHaikou 570288China Laboratory of Optical physics Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China College of Science Shantou UniversityShantou 515063China University of Chinese Academy of Sciences Beijing 100049China

We study the above-threshold ionization(ATI)process of atoms exposed to fundamental and high-frequency lasers with arbitrary ellipticity by applying the frequency-domain *** is found that the angular-resolved ATI spectrum is sensitive to ellipticities of two lasers and emitted angles of the *** for the photon energy of the highfrequency laser more than atomic ionization potential,the width of plateau tends to a constant with increasing ellipticity of fundamental field,the dip structure disappears with increasing ellipticity of the high-frequency *** the help of the quantum channel analysis,it is shown that the angular distribution depends mainly on the ellipticity of high-frequency field in the case that its frequency is ***,one can see that the maximal and minimal energies in quantum numerical results are in good agreement with the classical *** investigation may provide theoretical support for experimental research on polarization control of ionization in elliptically polarized two-color laser fields.

关键词： above-threshold ionization two-color laser polarization control

quantum coherent effects in multi-Zeeman-sublevel atomic systems

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2008年第9期17卷 3306-3312页

作者：董雅宾郜江瑞董有尔 Department of physics Shanxi University State Key Laboratory of quantum optics and quantum optics Devices Institute of Opto-ElectronicsShanxi University

This paper reports the experimental results on electromagnetically induced absorption （EIA） spectra observed in the system which does not satisfy completely the conditions given by Lezama et al [1999 Phys. Rev. A 59 4732]. EIA signals on the transitions in the Cs D2 line are able to be observed, where Fg ←→ Fe = Fg-1 as open systems. Theoretical model of Lezama et al is good for the case Fg ←→ Fc = Fg ＋ 1, considering spontaneous transfer of atomic coherences or populations this model is not able to explain our experimental results obtained in the case Fg ←→ Fe = Fg - 1. This paper offers a theoretical model which is able to well explain the case Fg ←→ Fc = Fg - 1. It also uses this theoretical model to explain the split and shift of EIA peaks, which have been obtained in experiments.

关键词： electromagnetically induced absorption multi-Zeeman-sublevel

Appropriate Gate Time for Single Molecular photon Detection Based on Optimal Signal-to-Noise Ratio Analyses

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2007年第5期24卷 1224-1227页

作者：董双丽黄涛刘源王俊肖连团贾锁堂 State Key Laboratory of quantum optics and quantum optics Devices College of Physics and Electronics Engineering Shanxi University Taiyuan 030006

Signal-to-noise ratio of fluorescence detection from a single molecule ＆ analysed by using time-gated techniques. It is found that the optimal signal-to-noise ratio can be obtained by choosing an appropriate gate time with a certain optical background. The dependences of molecular fluorescence lifetime and the optimal signal-to-noise ratio on the appropriate gate time are respectively discussed with two kinds of background sources~ chaotic state with uniform distribution and coherent state with exponential distribution in time domain. For chaotic state background we find that a certain range for appropriate gate time can be obtained with a definite fluorescence lifetime, larger fluorescence lifetime would lower the value of optimal signal-to-noise ratios. For coherent state background we find that there is also a narrow range of appropriate gate time when lifetime of single molecule is less than that of background photons.

关键词： FLUORESCENT MOLECULES ROOM-TEMPERATURE SPECTROSCOPY STATISTICS

photon statistics measurement for coherent fields

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese optics Letters 2008年第4期6卷 238-240页

作者：刘源王俊董双丽张国峰肖连团贾锁堂 State Key Laboratory of quantum optics and quantum optics Devices College of physics and Electronics Engineering Shanxi UniversityTaiyuan 030006

An efficient scheme for photon statistics measurement is presented based on the Hanbury-Brown-Twiss configuration. We set the sampling time Ts to satisfy the relationship of Ts 〈 Td 〈 Tm, where Td is the dead time of each detector and Tm is the laser pulse repetition period. And each single photon detector cannot detect more than one photon in each pulse. The approach can sufficiently eliminate the influences of the detector＇s dead time on photon statistics. At last, the photon statistics of coherent field is experimentally determined.

关键词： Coherent light Laser pulses photons