Observation of V-type electromagnetically induced transparency and optical switch in cold Cs atoms by using nanofiber optical lattice

Optical nanofiber(ONF)is a special tool to achieve the interaction between light and matter with ultralow power.In this paper,we demonstrate V-type electromagnetically induced transparency(EIT)in cold atoms trapped by an ONFbased two-color optical lattice.At an optical depth of 7.35,90%transmission can be achieved by only 7.7 pW coupling power.The EIT peak and linewidth are investigated as a function of the coupling optical power.By modulating the pWlevel control beam of the ONF-EIT system in sequence,we further achieve efficient and high contrast control of the probe transmission,as well as its potential application in the field of quantum communication and quantum information science by using one-dimensional atomic chains.

Entropy squeezing for a V-type three-level atom interacting with a single-mode field and passing through the amplitude damping channel with weak measurement

The entropy squeezing of a V-type three-level atom interacting with a single-mode field and passing through the amplitude damping channel is investigated in detail. Our results show that when coupled to the single-mode field, the atom in appropriate initial states can not only generate obvious entropy squeezing but also keep in the optimal squeezing state,while passing through the amplitude damping channel, the atom can generate entropy squeezing under the control of the weak measurement. Besides, it is proved again that as a measurement method for atomic squeezing, the entropy squeezing is precise and effective. Therefore our work is instructive for experiments in preparing three-level system information resource with ultra-low quantum noise.

Cross-Polarized Single Photon Emission from Single Semiconductor Quantum Dots with V-Type Level Driven by Pulse Field

The statistic properties of photon emissions from single semiconductor quantum dots with V-type leveldriven by pulses are investigated theoretically.Based on quantum regression theorem and master equations,the dynamicequations of the second-order correlation function of the photon emissions are deduced.The calculated results reveal thatthe efficiency of single photon emissions from two orthogonal polarization eigenstates(|x〉and |y〉)reaches the maximumwhen the input pulses area is about π,and the probability of the cross-polarized single photon emission from |x〉and |y〉decreases with increasing of pulse width.

Wave Defending Effects of V-Type Bottom-Mounted Breakwaters

An analytical method is developed for the study of the wave defending effects of the V-type bottom-mounted breakwater. The breakwater is assumed to be rigid, thin, impermeable and vertically located in water of constant depth. The fluid domain is divided into three sub-regions by an imaginary interface. The velocity potential in each region is expanded by eigenfunctions. By satisfying the corresponding boundary conditions and matching conditions in and between sub-regions, a set of linear algebraic equations can be obtained to determine the unknown coefficients for the eigenfunction expansions for each sub-region. The accuracy of the present model is verified by a comparison with existing results for the case of an isolated breakwater. Numerical results, in the form of contour maps of the relative wave amplitude around the breakwater, are presented for a range of wave and breakwater parameters. The results show that the V-type bottom-mounted breakwater is generally effective in defending against waves. In general, the wave height in the protected area is about 20～50 percent of the incident wave height.

Photon counting statistics of V-type three-level systems:The effects of the field fluctuations

We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems.The emission intensity I and Mandel＇s Q parameter show stochastic resonance with respect to the pure dephasing constantγp.The amplitude fluctuation of the field causes these systems to lose their coherence.On the other hand,the amplitude fluctuation provides a new interference method for these systems.The quantum beats are shown in the orthogonal system.

Complexation with pre-formed“empty”V-type starch for encapsulation of aroma compounds

Aroma compounds are low-molecular-weight organic volatile molecules and are broadly utilized in the food industry.However,due to their high volatility and evaporative losses during processing and storage,the stabilization of these volatile ingredients using encapsulation is a commonly investigated practice.Complexation of aroma compounds using starch inclusion complex could be a potential approach due to the hydrophobicity of the left-handed single helical structure.In the present study,we used starch of three different V-type structures,namely V,V,and V,to encapsulate six different aroma compounds,including1-decanol(DN),cis-3-hexen-1-ol(HN),4-allylanisole(AN),γ-decalactone(DA),trans-cinnamaldehyde(CA),and citral(CT).The formed inclusion complexes samples were characterized using complementary techniques,including X-ray diffraction(XRD)and differential scanning calorimetry(DSC).The results showed that upon complexation with aroma compounds,all V-subtypes retained their original crystalline structures.However,different trends of crystallinity were observed for each type of the prepared inclusion complexes.Additionally,among three V-type starches,V-type starch formed inclusion complexes with aroma compounds most efficiently and promoted the formation of FormⅡcomplex.This study suggested that the structure of aroma compounds and the type of V starch could both affect the complexation properties.

Generation of entangled coherent states for two cavity modes via resonant interaction with a V-type three-level atom

This paper proposes a scheme for the generation of entangled coherent states for two cavity modes. In the scheme a V-type three-level atom is sent through a two-mode cavity filled with a coherent field. After the atom cavity interaction and detection of the atomic state the cavity modes may evolve to a superposition of two-mode coherent states. As the scheme is based on resonant atom-cavity interaction, the required interaction time is short, which is important in view of the decoherence. Moreover, additional classical pulses are unnecessary before and after the atom-cavlty interaction.

Nonreciprocal Single Photon Frequency Conversion via Chiral Coupling between a V-Type System and a Pair of Waveguides

The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the real-space Hamiltonian. The calculated results show that the probability of single photon frequency down-or up-conversion can reach a unit by choosing appropriate parameters in the non-dissipative system with perfect chiral coupling.We present a nonreciprocal single photon beam splitter whose frequency of the output photon is different from that of the input photon. The influences of dissipations and non-perfect chiral coupling on the single frequency conversion are also shown. Our results may be useful in designing quantum devices at the single-photon level.

Characterization of Cytosolic V_1-ATPase in Pea Root

Cytosolic V-1-ATPase complex in pea (Pistum sativum L.) root cells was characterized by immunoblotting, immuno-electron microscopy and measurement of ATP hydrolysis activity. Using antibodies against the subunits A and B of V-type H+-ATPase (V-ATPase) from mung bean as primary antibodies, both immuno-blotting and immuno-electron microscopy showed that subunit A and subunit B existed in the cytosol. Measurement of ATPase activity further showed that cytosolic proteins had NO3--sensitive ATP hydrolysis activity. All these suggested that V-1-ATPase complex occurred in the cytosol. This is the direct proof that V-1-ATPase occurs in the cytosol of the plant cells for the first time.

Preparation of W state in resonant bimodal cavity quantum electrodynamics

A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a V-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity, the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three V-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.

Demonstration of the approximation of eliminating atomic excited populations in an atom-cavity system

Using the master equation approach to a V-type three-level atom inside a high-finesse single-mode cavity in the strong coupling condition, we demonstrate the approximation of eliminating populations of atomic excited states, which is widely used in the field of the atom cavity systems [Hechenblaikner G, Gangl M, Horak P and Ritsch H 1998 Phys. Rev. A 58 3030]; Liu L W, Tan T and Xu Y 2008 J. Mod. Opt. 56 968; Cho J, Angelakis D G and Bose S 2008 Phys. Rev. A 78 062338. This is reflected in the deviation of the population 5, of which the value is 10^-3 - 10^-2. We further find the deviation of the dipole force and demonstrate that the deviation of atomic population will not notably affect the dipole force of the atom in the strong coupling condition. A relevant experimental case is also presented.

MUTS-Based Cooperative Target Stalking for A Multi-USV System

This paper is concerned with the cooperative target stalking for a multi-unmanned surface vehicle(multi-USV)system.Based on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,a multi-USV target stalking(MUTS)algorithm is proposed.Firstly,a V-type probabilistic data extraction method is proposed for the first time to overcome shortcomings of the MADDPG algorithm.The advantages of the proposed method are twofold:1)it can reduce the amount of data and shorten training time;2)it can filter out more important data in the experience buffer for training.Secondly,in order to avoid the collisions of USVs during the stalking process,an action constraint method called Safe DDPG is introduced.Finally,the MUTS algorithm and some existing algorithms are compared in cooperative target stalking scenarios.In order to demonstrate the effectiveness of the proposed MUTS algorithm in stalking tasks,mission operating scenarios and reward functions are well designed in this paper.The proposed MUTS algorithm can help the multi-USV system avoid internal collisions during the mission execution.Moreover,compared with some existing algorithms,the newly proposed one can provide a higher convergence speed and a narrower convergence domain.

Effect of structural parameters on the hydrodynamic performance of vertical curved V-Type otter board

In order to study the influence mechanism of structural type and size on the hydrodynamic performance of vertical curved V-type otter board,this paper based on the computational fluid dynamics method,a three-dimensional numerical model of vertical curved V-type otter board is established to calculate and analyze its hydrodynamic performance,and the validity of the numerical simulation results is verified by designing and constructing a scaled model for dynamic flume experiments.On this basis,the effects of different structural parameters,such as the deflector angle,camber,and spacing,on the hydrodynamic performance of the vertical curved V-Type otter board are investigated and the optimal structural design scheme is determined.The results demonstrate that single or synchronous changes of the angle,camber,and spacing of the two deflectors have varying degrees of impact on the hydrodynamic performance of the vertical curved V-Type otter board.To improve the expansion effect of the otter board,setting the angle of the deflector A to 40◦and that of the deflector B to 30◦,or setting the camber of deflectors A and B to 18%,or setting the spacing between deflectors A and B to 380 mm and that between the deflector and the main panel to 670 mm can increase the lift coefficient of the vertical curved V-Type otter board to its maximum value.Considering the overall performance of the otter board,when the angle of the deflector A is set to 25◦and that of the deflector B is set to 30◦,or the camber of the deflector A is set to 6% and that of the deflector B is set to 9%,or the spacing between deflectors A and B is set to 340 mm and that between the deflector and the main panel is set to 610 mm,the lift-to-drag ratio of the otter board can be increased to its maximum value.

Teleporting N-qubit unknown atomic state by utilizing the V-type three-level atom

Realizing the teleportation of quantum state, especially the teleportation of N-qubit quantum state, is of great importance in quantum information. In this paper, Raman-interaction of the V-type degenerate three-level atom and single-mode cavity field is studied by utilizing complete quantum theory. Then a new scheme for teleporting N-qubit unknown atomic state via Raman-interaction of the V-type degenerate three-level atom with a single-mode cavity field is proposed, which is based upon the complete quantum theory mentioned above.

Effect of Doppler broadening on gain in an open V-type inversionless lasing system

Our study shows that for the copropagating probing and driving fields, the gain without inversion doesn't monotonously decrease or increase with the increasement of Doppler width. When the driving field is resonant, at a suitable Doppler width, we can get a maximum value of the gain without inversion, which is much larger than that obtained when Doppler broadening is absent.

Controllable single-photon transport in an optical waveguide coupled to an optomechanical cavity with a V-type three-level atom

An optomechanical cavity embedded with a V-type three-level atom is exploited to control single-photon transport in a one-dimensional waveguide. The effects of the atom–cavity detuning, the optomechanical effect,the coupling strengths between the cavity and the atom or the waveguide, and the atomic dissipation on the single-photon transport properties are analyzed systematically. Interestingly, the single-photon transmission spectra show multiple double electromagnetically induced transparency. Moreover, the double electromagnetically induced transparency can be switched to a single one by tuning the atom–cavity detuning.

High permittivity of Ba(Ti_(1-x)Zr_(x))O_(3)-based Y5V-type nanopowders and ceramics synthesized using a one-step sol-gel method

We synthesized Ba(Ti_(1-x)Zr_(x))O_(3)-based(BTZ)nanopowders modified with Cu and Nb,and sintered ceramics using a one-step sol-gel process.Characterization using TG-DTG,XRD,SEM,and TEM analysis methods revealed that the powders formed at a nanometer scale.The process was controlled by the composition and calcining temperature.BaZrO3 formed earlier than BaTiO3 during the calcining,then a Ba(Ti_(1-x)Zr_(x))O_(3) solid solution formed incompletely,resulting in ceramics with huge permittivity and good temperature stability.Moreover,the maximum dielectric constant(εmax)first increased and then decreased as the Curie temperature(Tc)shifted to a lower temperature.When the Zr concentration was 5.4 mol%,εmax was greater than 24,000 and the dielectric loss(25℃)was only 0.005;this meets the Electronic Industries Alliance Y5V specifications.These nanopowders would permit a significant reduction in the thickness of multilayer ceramic capacitors and the huge pemittivity of the ceramics will help meet the current demand for device miniaturization in the electronics industry.

Non-Markovian and Markovian Dynamics of a V-type Three-Level Atom

Abstract The reduced dynamics of a V-type three-level atom in a structure reservoir is presented, which has the exact solution in certain special condition. The Markovian and non-Markovian master equations for this composite system are solved and compared with the exact solution. The solving approach can be directly generalized to the solution of a V-type multilevel system dynamics interacting with a reservoir. The results further testify that these two kinds of master equations are exploited in different coupling regime, providing guidance for further application of these variants master equations to solve multilevel system dynamics without the exact solution.

Analytical and technological aspects of amylose inclusion complexes for potential applications in functional foods

The linear component of starch,amylose,has the ability to interact with hydrophobic molecules forming inclusion complexes(ICs).These structures have gained a particular interest for potential food applications,either as dietary fiber or as delivery systems of bioactive compounds.In the second case,the complexation of sensitive molecules is directed to protect them from processing,storage and stomach conditions and to guarantee a sustained release in the gastrointestinal tract.The present review covers the analytical and technological aspects of inclusion complexes,with focus on their potential application in the development of functional foods.It was addressed by first explaining the methodologies used for the analytical assessment of their structural,thermal,and functional properties,followed by the study of the functionality of ICs as carrier agents of different bioactive compounds and food ingredients,including alpha-lipoic acid,α-linolenic and linoleic fatty acids,conjugated linoleic acid,ascorbyl palmitate,phenolic compounds,and flavors.It also covers the application of ICs in food products and the analysis of the potential industrial scalability of the formation process.The analytical methodologies allowed a complete characterization of the ICs.These structures have shown suitable functional properties as delivery systems of the bioactive compounds and flavors covered in this review.The incorporation of ICs in food has led to the development of products with improved nutritional and/or functional value.The successful formation of complexes using methods suitable for an industrial scale represents promising preliminary results to achieve the scalability of the ICs production in the near future.