量子光力系统中激光额外噪声的高效抑制（英文）

采用级联非平衡马赫-曾德光纤干涉仪来降低激光额外噪声,并实验证明了其可行性及激光噪声抑制效果.当光纤干涉仪两臂长度差为127m时,通过自制的自动相位锁定装置,可以长时间稳定地将干涉仪两臂的相对相位锁定在零相位,此时激光光场在800kHz及其整数倍频率处的额外噪声得到高效地抑制,降低幅度可达45dB以上.调节干涉仪的两臂差,可以改变噪声过滤的频段.基于该方法的噪声抑制装置结构紧凑、成本低,可应用于量子光力系统中散粒噪声极限光场的获得.

Smaller Ge Quantum Dots Obtained by ArF Excimer Laser Annealing

Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bulk diffusion is forbidden,and only surface diffusion occurs, resulting in a laser induced quantum dot （LIQD）. The diameter of the LIQD is 20-25nm which is much smaller than the as-grown dot and the LIQD has a higher density of about 6 ×10^10cm^-2. The surface morphology evolution is investigated by AFM.

Transport Properties of Two Coupled Quantum Dots Under Optical Pumping

Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission coefficient occur and can be explained by the local electron density of states in the quantum dots. The effects of the optical pumping frequency and intensity on the transport properties of the system are also discussed. The electron dynamical localization phenomenon occurs when the optical pumping frequency is equal to the discrete hole energy level. This result can be used to realize optical control switches.

Interferences in Photodetachment of a Negative Molecular Ion Model

By employing a two-center model, the total and differential cross sections in the photodetachment of ＂a negative molecular ion＂ are studied theoreticedly and obtained for the case of light polarization paredlel to the molecular axis. We find that in contrast to the smooth behavior of the total cross section for perpendicular polarized light, the cross section for parallel polarized light shows an interesting oscillatory structure. The oscillations in the toted cross section may provide a method to determine the distance between the two centers. We explain the oscillation in the toted cross section as an interference effect using closed-orbit theory. We also cedculated the detached-electron flux distributions on a screen placed at a large distance from the negative molecular ion. The distributions display multiple-ring-like interference patterns. Such interference patterns are similar to those in the photodetachment microscopy experiments.

Energy Spectra of a Magnetic Quantum Ring with an Off-Center Impurity

In this paper, we calculate the low-lying spectra of a single-electron magnetic quantum ring with an offcenter Coulomb impurity, where the magnetic field is zero within the ring and constant elsewhere. The impurity, either an acceptor or a donor, is located at a distance d as measured from the plane of the ring along the vertical z direction. The magnetic moments are found in order to get visible discontinuities at the points of the ground-state orbital angular momentum L transitions induced by magnetic fields.

Exact Solution for Phenomenon of atomic Collapse and Revival under Rotating Wave and Anti-Rotating Wave Approximation

An accurate method to solve the daynes Cummings （J-C） Hamiltonian has been investigated here. The phenomenon of atomic collapse and revival predicted by Jaynes-Cummings model is demonstrated. Solutions are consis- tent with the precious such as using the operator method. Furthermore, the Jaynes-Cummings Hamiltonian including the anti-rotating term is also solved precisely using this accurate way so that results agree with experiments better. Essences of the anti-rotating term are revealed. We discuss the relations of the phenomenon of atomic collapse and revival with the average photons number, the light field phase angle, the resonant frequency, and the size of coupling constant. The discussions may make one select suitable conditions to carry out experiment well and study the virtual light field effect on cavity quantum electrodynamics.

Dynamics of Optically Driven Exciton and Quantum Decoherence

By using the normal ordering method, we study the state evolution of an optically driven excitons in a quantum well immersed in a leaky cavity, which was introduced by Yu-Xi Liu et al. [Phys. Rev. A 63 (2001) 033816]. The influence of the external laser field on the quantum decoherence of a mesoscopically superposed state of the excitons is investigated. Our result shows that, the classical field can compensate the energy dissipation of the excitons. Although the decoherence rate of the excitonic Schr?dinger cat state does not depend on the external field, the phase of the decoherence factor can be well controlled by adjusting the amplitude of the external field as well as the detuning between the field and the transition frequency of the atom.

Coherent-Entangled State in Three-Mode and Its Applications

We introduce the new concept of coherent-entangled state （CES）. By virtue of the technique of integration within an ordered product of operators we introduce a new kind of three-mode CES [β,γ,x）, which exhibits both properties of the coherent state and the entangled state. [β,γ,x） makes up a new quantum mechancial representation. Its applications in quantum optics are also presented.

Quantum Mechanical Version for Bessel Beam's Propagation in ABCD Optical System

By introducing the entangled state representation and the two-mode Fresnel operator we provide quantum mechanical version for Bessel beam＇s classical propagation in ABCD optical system. This provides the opportunity of studying various classical Fresnel transformations in the context of quantum optics.

The Top－Charm Associated Production Within the R－Parity Violating Supersymmetric Model in Photon－Proton Collisions

The top-charm associated production with the effects from both B- and L-violating interactions in TeV scale photon-proton collisions is investigated in the framework of minimal supersymmetric standard model. Within the bounds on the relevant R-parity violating couplings, the total cross section will reach the order of 10 fb in some parts of the parameter space.

Interactive Lagrangian density between massive photons and gravitons

The interactive Lagrangian density of massive photons and gravitons is proposed after an investigation into the interaction between photons with or without mass under the influence of gravity either as classical field, gravitational wave, or gravitons from a perspective of quantum field. This interactive Lagrangian density can provide a step-stone for further research of gravitational wave and the possible rest mass of photon.

Optical Test of Local Hidden—Variable Model

An inequality is deduced from local realism and a supplementary assumption. This inequality defines an experiment that can be actually performed with the present technology to test local hidden-variable models, and it is violated by quantum mechanics with a factor 1.92, while it can be simplified into a form where just two measurements are required.

SUSY QCD Impact on Top-Pair Production Associated with a Z^0-Boson at a Photon-Photon Collider

The top-pair production in association with a Z^0-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD （SQCD） next-to-leading order （NLO） radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model （SM） QCD. We investigate the dependence of the lowest-order （LO） and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model （MSSM） on colliding energy √s in different polarized photon collision modes. The LO, SM NLO, and SQCD NLO corrected distributions of the invariant mass of tt^--pair and the transverse momenta of final Z^0-boson are presented. Our numerical results show that the pure SQCD effects in γγ →tt^- Z^0 process can be more significant in the ＋＋ polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to -1.89% when √s goes up from 500 GeV to 1.5 TeV.

A robust method to measure residual stress in micro-structure

An experimental investigation on the residual stress in porous silicon micro-structure by means of micro-Raman spectros- copy is presented. It is shown by detecting the Raman peak shifts on the surfaces and cross-sections of electrochemical etched porous silicon samples with different porosities that serious residual stresses distribute complicatedly within the whole porous silicon structure. It is proved that micro-Raman spectroscopy is an effective method for residual stress testing on the micro-structures applied in optoelectronics and microelectronics.

Effects of Artificial Aging on Seed Vigor and Ultraweak Luminescence of Wheat Seeds

In order to ascertain the effect of artificial aging on ultraweak lumines- cence （UWL） and the correlation between UWL and seed vigor, and explore a new way of seed vigor non-destructive testing, seeds of wheat variety ‘Jimai 22＇ were used to study the change of UWL intensity and its relationship to seed vigor and ATP content during artificial aging. The results showed that with the extension of artificial aging time, the germination percentage, germination potential, germination index, UWL intensity and ATP content decreased gradually; after artificial aging for 48 h, they were reduced by 19.19%, 34.34%, 38.78%, 27.77% and 13.84%, re- spectively, compared with CK. Correlation analysis indicated that the UWL intensity was significantly positive correlated with germination percentage, germination poten- tial, germination index and ATP content. It was concluded that UWL as a fast, non- destructive and sensitive detection method could be applied in the study of seed vigor non-destructive testing.

Quantum Entanglement Dynamics of Two Atoms in Quantum Light Sources

Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time,which depends on the initial atomic states and the properties of squeezed states.We find that there are two decoherencefreestates in squeezed vacuum fields:one is the singlet state,and the other entangled state is the state that combinesboth excited states and ground states with a relative phase being equal to the phase of the squeezed state.

Dynamics of Two-Photon Lasers with A Atomic Level Configuration

We derive the dimensionless dynamic equations of two-photon lasers with A atomic level configuration by using the quantum Langevin equation method with the considerations of atomic coherence and injected classical fields. Then we analyze the stability and the chaotic dynamics of the two-photon laser by calculating the bifurcation diagram and the maximum Lyapunov exponent （MLE）. Our results show that the Lorenz strange attractors and one-focus strange attractors can exist in this system, and the chaos can be induced or inhibited by the injected classical fields via Hopfbifurcations or crises, while the atomic coherence induces chaos via crises, and inhibit chaos via Hopf bifurcation or crises.

Wave Mechanics or Wave Statistical Mechanics

By comparison between equations of motion of geometrical optics and that of classical statistical mechanics, this paper finds that there should be an analogy between geometrical optics and classical statistical mechanics instead of geometrical mechanics and classical mechanics. Furthermore, by comparison between the classical limit of quantum mechanics and classical statistical mechanics, it finds that classical limit of quantum mechanics is classical statistical mechanics not classical mechanics, hence it demonstrates that quantum mechanics is a natural generalization of classical statistical mechanics instead of classical mechanics. Thence quantum mechanics in its true appearance is a wave statistical mechanics instead of a wave mechanics.

Dynamics and entanglement of a membrane-in-the-middle optomechanical system in the extremely-large-amplitude regime

The study of optomechanical systems has attracted much attention, most of which are concentrated in the physics in the smallamplitude regime. While in this article, we focus on optomechanics in the extremely-large-amplitude regime and consider both classical and quantum dynamics. Firstly, we study classical dynamics in a membrane-in-the-middle optomechanical system in which a partially reflecting and flexible membrane is suspended inside an optical cavity. We show that the membrane can present self-sustained oscillations with limit cycles in the shape of sawtooth-edged ellipses and exhibit dynamical multistability. Then, we study the dynamics of the quantum fluctuations around the classical orbits. By using the logarithmic negativity, we calculate the evolution of the quantum entanglement between the optical cavity mode and the membrane during the mechanical oscillation. We show that there is some synchronism between the classical dynamical process and the evolution of the quantum entanglement.

Self-assembled nanostructured photosensitizer with aggregation-induced emission for enhanced photodynamic anticancer therapy

Three nanostructured photosensitizers with aggregation-induced emission(AIE) characteristics based on2,3-bis(4?-(diphenylamino)-[1,1?-biphenyl]-4-yl) fumaronitrile(BDBF) were prepared for image-guided photodynamic therapy(PDT). BDBF was encapsulated with Pluronic F-127(F127) to form usual spherical nanoparticles(F127@BDBF NPs) with a red fluorescence emission and 9.8% fluorescence quantum yield(FQY). Moreover, BDBF self-assembled into nanorods(BDBF NRs) in water. Compared with F127@BDBF NPs, BDBF NRs exhibited stronger orange fluorescence with a higher FQY of 23.3% and similar singlet oxygen(1O2) generation capability. BDBF NRs were further modified with F127 to form BDBF@F127 NRs with the same 1O2 generation ability as BDBF NRs. The three nanostructures exhibited a higher 1O2 production capacity than BDBF molecule in dissolved state and favorable stability in an aqueous solution as well as under physiological condition. In vitro photocytotoxicity experiments indicated that the three nanostructures inhibited tumor cell proliferation effectively.Therefore, to construct eligible nanostructures with a high FQY and 1O2 generation ability, simple self-assembly can serve as a valuable method to prepare photosensitizers with enhanced PDT.