We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. T...We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. Theinfluences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification)are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced dueto the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibitsthe double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On thecontrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved byadjusting the coherent pump field intensity in the absence of the spontaneously generated coherence.展开更多
In this paper, we study remote state preparation (RSP) by w state through noisy channels. The trace distance is used to describe how close the original state is to the output state. Studies show the trace distance is ...In this paper, we study remote state preparation (RSP) by w state through noisy channels. The trace distance is used to describe how close the original state is to the output state. Studies show the trace distance is a function of decohenrence rates and angles of the state to be prepared. At the same time, we investigate the influence of different types of noises on the trace distance and find the various types of noises have different degrees of influence on the trace distance for a definite qubit. We also study changes of the trace distance against polar and azimuthal angles.展开更多
In this paper, we discuss and analyze theoretically probe absorption-amplification response in a four-level coherent atomic system with vacuum-induced coherence via changing the sign of the parameter f, with f denotin...In this paper, we discuss and analyze theoretically probe absorption-amplification response in a four-level coherent atomic system with vacuum-induced coherence via changing the sign of the parameter f, with f denoting the ratio of a pair of dipole moments associated with a doublet of closely upper hyperfine sublevels. We find that the amplitude of the probe amplification for the case f = -1 can be about one order of magnitude larger than that achievable for the case f = 1. In addition, with respect to the case f = -1 the probe amplification can be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.展开更多
We obtain the exact analytical results of all the eigenvalues and eigenstates for three kinds of models describing N-mode multiphoton process without using the assumption of the Bethe ansatz. The exact analytical resu...We obtain the exact analytical results of all the eigenvalues and eigenstates for three kinds of models describing N-mode multiphoton process without using the assumption of the Bethe ansatz. The exact analytical results of all the eigenstates and eigenvalues are in terms of a parameter λ for three kinds of models describing N-mode multiphoton process. The parameter is shown to be determined by the roots of a polynomial and is solvable analytically or numerically. Moreover, these three kinds of models can be processed with the same procedure.展开更多
In this paper,we propose and analyze an optical multi-wave mixing scheme for the generation of coherent light in a five-level atomic system in the context of electomagneticall induced transparency.A detailed semiclass...In this paper,we propose and analyze an optical multi-wave mixing scheme for the generation of coherent light in a five-level atomic system in the context of electomagneticall induced transparency.A detailed semiclassical study of the propagation of generated mixing and probe fields is demonstrated.The analytical dependence of the generated minxing field on the probe field and the respective detuning is predicted.Such a nonlinear optical process can be used for generating short-wavelength radiation at low pump intensities.展开更多
A scheme is proposed to generate arbitrary, discrete superpostions of squeezed coherent states of the squeezed center of mass of N trapped ions along a straight line in phase space. The scheme is based on a resonant b...A scheme is proposed to generate arbitrary, discrete superpostions of squeezed coherent states of the squeezed center of mass of N trapped ions along a straight line in phase space. The scheme is based on a resonant bichromatic excitation of each trapped ion that generates displacement and squeezing in the vibrational motion conditioned to each internal state. In this paper, we also show that such a method can be used for the engineering of motional quantum states.展开更多
We present an efficient approach to studying the spectra and eigenstates for the model describing interactionsamong five bosonic modes without using the assumption of the Bethe ansatz. The exact analytical results of ...We present an efficient approach to studying the spectra and eigenstates for the model describing interactionsamong five bosonic modes without using the assumption of the Bethe ansatz. The exact analytical results of all theeigenstates and eigenvalues are in terms of a parameter λ for a class of models describing five-mode multiphoton process.The parameter is determined by the roots of a polynomial and is solvable analytically or numerically.展开更多
In this paper, we analyze and discuss the absorption properties of the probe beam in a four-level atomic system with a nearly hyper-fine doublet structure of two higher-lying excited levels based on electromagneticall...In this paper, we analyze and discuss the absorption properties of the probe beam in a four-level atomic system with a nearly hyper-fine doublet structure of two higher-lying excited levels based on electromagnetically induced transparency (EIT) for the two cases of transient process and steady-state process. The main gain of this work is to investigate theoretically the influence of the nearly hyper-fine levels on the probe absorption. For the transient process,using the numerical calculations by a simple Mathematica code we find that the magnitude of the probe absorption at the line center is small compared to the typical three-level atomic system in the context of electromagnetically induced transparency. For the case of the steady state, our results show that the probe absorption can be completely eliminated at the line center of the probe transition just as the usual three-level EIT scheme.展开更多
In this paper, using the arguments of Wu et al. [Phys. Rev. Left. 86 (2001) 2200] we analytically discuss the energy spectra and corresponding eigenstates for the process of κ-photon down-conversion with quantized p...In this paper, using the arguments of Wu et al. [Phys. Rev. Left. 86 (2001) 2200] we analytically discuss the energy spectra and corresponding eigenstates for the process of κ-photon down-conversion with quantized pump in a high-Q cavity by the aid of the computer programme. Remarkably, it is also shown that such a method can be used for solving numerically the equations in a much simpler manner than the previous ones.展开更多
We demonstrate the efficient generation of coherent light in a four-level double-cascade atomic medium by continuous-wave low-intensity laser radiation. We derive the corresponding explicit analytical expressions for ...We demonstrate the efficient generation of coherent light in a four-level double-cascade atomic medium by continuous-wave low-intensity laser radiation. We derive the corresponding explicit analytical expressions for the generated four-wave mixing (FWM) field. Dependencies of the intensity of the generate FWM field on the propagation distance, on the input-wave intensity, and on the photon detuning are investigated. To conclude, we also give a brief discussion on the experimental realization of the proposed scheme.展开更多
We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of up...We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.展开更多
We discuss the generation of certain kinds of multi-component entangled states for three-level atomic system with hyperfine structure. The method proposed here is based on the interactions of dispersive cavity with on...We discuss the generation of certain kinds of multi-component entangled states for three-level atomic system with hyperfine structure. The method proposed here is based on the interactions of dispersive cavity with only one atom driven by a strong classical field. It is shown that, with a judicious choice of the cavity detuning and applied coherent field detuning, the atom can interact dispersively with the quantized field but the classical driving field gives rise to the creation or destruction of photons conditional on the state of the system. In comparison with previous schemes,our method is likely to be extremely easy to realize in展开更多
The. Analytical expressions of eigenstates and eigenenergies are demonstrated using a parameter λ without the assumption of Bethe anstz for two kinds of N-mode mixing models. The parameter is shown to be determined b...The. Analytical expressions of eigenstates and eigenenergies are demonstrated using a parameter λ without the assumption of Bethe anstz for two kinds of N-mode mixing models. The parameter is shown to be determined by the roots of a simple polynomial and is solvable analytically or numerically. In addition, the exact analytical expressions of eigenstates and eigenenergies are illustrated without any unknown parameter.展开更多
Using Schrodinger-Maxwell formalism, we propose and analyze an optical four-wave mixing (FWM) scheme for the generation of coherent light in a coherent six-level atomic medium based on dual electromagnetically induced...Using Schrodinger-Maxwell formalism, we propose and analyze an optical four-wave mixing (FWM) scheme for the generation of coherent light in a coherent six-level atomic medium based on dual electromagnetically induced transparency (EIT). We show that the significantly enhanced conversion efficiency enabled by ultraslow propagation of pump waves has no direct relationship with the single-photon detuning, which is different from the FWM with a single EIT. The most important feature is that our scheme is also capable of inhibiting and delaying the onset of the detrimental three-photon destructive interference that looks like a recent scheme [Phys. Rev. Lett. 91 (2003) 243902] andmay be used for generating short-wave-length coherent radiation.展开更多
We present a scheme of preparing the tripartite W state among three cavity modes of radiation field inside high-Q superconducting cavities. Our scheme is based on the interaction of a four-level atom with the cavity f...We present a scheme of preparing the tripartite W state among three cavity modes of radiation field inside high-Q superconducting cavities. Our scheme is based on the interaction of a four-level atom with the cavity field for precalculated interaction times with every mode.展开更多
文摘We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. Theinfluences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification)are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced dueto the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibitsthe double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On thecontrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved byadjusting the coherent pump field intensity in the absence of the spontaneously generated coherence.
文摘In this paper, we study remote state preparation (RSP) by w state through noisy channels. The trace distance is used to describe how close the original state is to the output state. Studies show the trace distance is a function of decohenrence rates and angles of the state to be prepared. At the same time, we investigate the influence of different types of noises on the trace distance and find the various types of noises have different degrees of influence on the trace distance for a definite qubit. We also study changes of the trace distance against polar and azimuthal angles.
文摘In this paper, we discuss and analyze theoretically probe absorption-amplification response in a four-level coherent atomic system with vacuum-induced coherence via changing the sign of the parameter f, with f denoting the ratio of a pair of dipole moments associated with a doublet of closely upper hyperfine sublevels. We find that the amplitude of the probe amplification for the case f = -1 can be about one order of magnitude larger than that achievable for the case f = 1. In addition, with respect to the case f = -1 the probe amplification can be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.
文摘We obtain the exact analytical results of all the eigenvalues and eigenstates for three kinds of models describing N-mode multiphoton process without using the assumption of the Bethe ansatz. The exact analytical results of all the eigenstates and eigenvalues are in terms of a parameter λ for three kinds of models describing N-mode multiphoton process. The parameter is shown to be determined by the roots of a polynomial and is solvable analytically or numerically. Moreover, these three kinds of models can be processed with the same procedure.
基金The project supported by National Fundamental Research Program of China under Grant No.2001CB309310
National Natural Science Foundation of China under Grant Nos.90103026,10125419,and 10121503
文摘In this paper,we propose and analyze an optical multi-wave mixing scheme for the generation of coherent light in a five-level atomic system in the context of electomagneticall induced transparency.A detailed semiclassical study of the propagation of generated mixing and probe fields is demonstrated.The analytical dependence of the generated minxing field on the probe field and the respective detuning is predicted.Such a nonlinear optical process can be used for generating short-wavelength radiation at low pump intensities.
文摘A scheme is proposed to generate arbitrary, discrete superpostions of squeezed coherent states of the squeezed center of mass of N trapped ions along a straight line in phase space. The scheme is based on a resonant bichromatic excitation of each trapped ion that generates displacement and squeezing in the vibrational motion conditioned to each internal state. In this paper, we also show that such a method can be used for the engineering of motional quantum states.
文摘We present an efficient approach to studying the spectra and eigenstates for the model describing interactionsamong five bosonic modes without using the assumption of the Bethe ansatz. The exact analytical results of all theeigenstates and eigenvalues are in terms of a parameter λ for a class of models describing five-mode multiphoton process.The parameter is determined by the roots of a polynomial and is solvable analytically or numerically.
文摘In this paper, we analyze and discuss the absorption properties of the probe beam in a four-level atomic system with a nearly hyper-fine doublet structure of two higher-lying excited levels based on electromagnetically induced transparency (EIT) for the two cases of transient process and steady-state process. The main gain of this work is to investigate theoretically the influence of the nearly hyper-fine levels on the probe absorption. For the transient process,using the numerical calculations by a simple Mathematica code we find that the magnitude of the probe absorption at the line center is small compared to the typical three-level atomic system in the context of electromagnetically induced transparency. For the case of the steady state, our results show that the probe absorption can be completely eliminated at the line center of the probe transition just as the usual three-level EIT scheme.
文摘In this paper, using the arguments of Wu et al. [Phys. Rev. Left. 86 (2001) 2200] we analytically discuss the energy spectra and corresponding eigenstates for the process of κ-photon down-conversion with quantized pump in a high-Q cavity by the aid of the computer programme. Remarkably, it is also shown that such a method can be used for solving numerically the equations in a much simpler manner than the previous ones.
文摘We demonstrate the efficient generation of coherent light in a four-level double-cascade atomic medium by continuous-wave low-intensity laser radiation. We derive the corresponding explicit analytical expressions for the generated four-wave mixing (FWM) field. Dependencies of the intensity of the generate FWM field on the propagation distance, on the input-wave intensity, and on the photon detuning are investigated. To conclude, we also give a brief discussion on the experimental realization of the proposed scheme.
文摘We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.
文摘We discuss the generation of certain kinds of multi-component entangled states for three-level atomic system with hyperfine structure. The method proposed here is based on the interactions of dispersive cavity with only one atom driven by a strong classical field. It is shown that, with a judicious choice of the cavity detuning and applied coherent field detuning, the atom can interact dispersively with the quantized field but the classical driving field gives rise to the creation or destruction of photons conditional on the state of the system. In comparison with previous schemes,our method is likely to be extremely easy to realize in
文摘The. Analytical expressions of eigenstates and eigenenergies are demonstrated using a parameter λ without the assumption of Bethe anstz for two kinds of N-mode mixing models. The parameter is shown to be determined by the roots of a simple polynomial and is solvable analytically or numerically. In addition, the exact analytical expressions of eigenstates and eigenenergies are illustrated without any unknown parameter.
文摘Using Schrodinger-Maxwell formalism, we propose and analyze an optical four-wave mixing (FWM) scheme for the generation of coherent light in a coherent six-level atomic medium based on dual electromagnetically induced transparency (EIT). We show that the significantly enhanced conversion efficiency enabled by ultraslow propagation of pump waves has no direct relationship with the single-photon detuning, which is different from the FWM with a single EIT. The most important feature is that our scheme is also capable of inhibiting and delaying the onset of the detrimental three-photon destructive interference that looks like a recent scheme [Phys. Rev. Lett. 91 (2003) 243902] andmay be used for generating short-wave-length coherent radiation.
文摘We present a scheme of preparing the tripartite W state among three cavity modes of radiation field inside high-Q superconducting cavities. Our scheme is based on the interaction of a four-level atom with the cavity field for precalculated interaction times with every mode.