Entangled squeezed coherent states: generation and their nonclassical properties in comparison with other entangled states (original) (raw)
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In this paper, after a brief review on the coherent states and squeezed states, we introduce two classes of entangled coherent-squeezed states. Next, in order to generate the introduced entangled states, we present a theoretical scheme based on the resonant atom-field interaction. In the proposed model, a Λ-type three-level atom interacts with a two-mode quantized field in the presence of two strong classical fields. Then, we study the amount of entanglement of the generated entangled states using the concurrence and linear entropy. Moreover, we evaluate a few of their nonclassical properties such as photon statistics, second-order correlation function, and quadrature squeezing and establish their nonclassicality features.
Applied Physics B, 2017
Recently, we introduced and generated new types of two-mode entangled states named “entangled coherent-squeezed states”. In these states, two common states for quantum information processing, coherent state and squeezed states have been used. Now, based on the generated entangled states, we introduce “two-mode photon-added entangled coherent-squeezed states”. These states are obtained vi the iterated action of two creation operators on the two modes of the “entangled coherent-squeezed states”. Next, we study the amount of entanglement of the introduced states using concurrence criterion. In the continuation, some of the nonclassical features such as photon-statistics, second-order correlation function and quadrature squeezing are considered. In addition, we study the influence of photon-addition of two modes on the mentioned properties of the introduced states. We will observe that the entanglement of the introduced photon-added entangled states increases more rapidly as photon-addition of two modes increases. Moreover, some of the nonclassical features for the first mode of the introduced states such as sub-Poissonian photon-statistics and squeezing in p appear and disappear by photon-addition of two modes, respectively.
Excitation and depletion of entangled squeezed states: their properties and generation
Physica Scripta, 2015
Recently, two-mode entangled squeezed states have been produced using even and odd squeezed states. Based on such entangled states, we introduce two new classes of quantum states, namely single-mode excited (depleted) entangled squeezed states which are obtained via the iterated action of the creation (annihilation) operator on the first mode of the two-mode entangled squeezed states. In continuation, we study the amount of entanglement of the introduced states by calculating the 'concurrence' and 'linear entropy'. In addition, we investigate several nonclassicality features such as the sub-Poissonian statistics, second-order correlation function between the two modes and quadrature squeezing. Finally, in order to establish the physical realization of the introduced states, a theoretical scheme for their generation based on the interaction of a two-level atom with a quantized cavity field is proposed.
Generation of entangled squeezed states: their entanglement and quantum polarization
Laser Physics, 2015
In this paper, based on the well-known one-mode and two-mode squeezed states, we introduce the two-mode and four-mode entangled squeezed states. Next, in order to generate the introduced entangled states, we present two theoretical schemes based on the resonant atom-field interaction. In the proposed schemes, a Λ-type three-level atom interacts with the two-mode and four-mode quantized field in the presence of two strong classical fields in which two-photon atomic transitions are allowed. In the continuation, we study entanglement dynamics of the generated entangled states (using the von Neumann entropy) as well as the quantum polarization (using the Stokes operators). It is demonstrated that entanglement and polarization can be achieved for the produced states by adjusting the evolved parameters.
Chinese Physics B, 2016
In this paper, after a brief review on the entangled squeezed states, we produce a new class of the continuous-variable-type entangled states, namely, deformed photon-added entangled squeezed states. These states are obtained via the iterated action of the f-deformed creation operator A = f (n)a † on the entangled squeezed states. In the continuation, by studying the criteria such as the degree of entanglement, quantum polarization as well as sub-Poissonian photon statistics, the two-mode correlation function, one-mode and two-mode squeezing, we investigate the nonclassical behaviors of the introduced states in detail by choosing a particular f-deformation function. It is revealed that the above-mentioned physical properties can be affected and so may be tuned by justifying the excitation number, after choosing a nonlinearity function. Finally, to generate the introduced states, we propose a theoretical scheme using the nonlinear Jaynes–Cummings model.
Entangled coherent states by mixing squeezed vacuum and coherent light
2017
Entangled coherent states are shown to emerge, with high fidelity, when mixing coherent and squeezed vacuum states of light on a beam-splitter. These maximally entangled states, where photons bunch at the exit of a beamsplitter, are measured experimentally by Fock-state projections. Entanglement is examined theoretically using a Bell-type nonlocality test and compared with ideal entangled coherent states. We experimentally show nearly perfect similarity with entangled coherent states for an optimal ratio of coherent and squeezed vacuum light. In our scheme, entangled coherent states are generated deterministically with small amplitudes, which could be beneficial, for example, in deterministic distribution of entanglement over long distances.
New type of two-photon squeezed coherent states
Physical Review D, 1985
A new set of non-naive generalizations of the squeezed coherent states recently discussed by Fisher, Nieto, and Sandberg is given, based on generalized Bose operators.
Entangled coherent states created by mixing squeezed vacuum and coherent light
Optica, 2019
Entangled coherent states are shown to emerge, with high fidelity, when mixing coherent and squeezed vacuum states of light on a beam-splitter. These maximally entangled states, where photons bunch at the exit of a beam-splitter, are measured experimentally by Fock-state projections. Entanglement is examined theoretically using a Bell-type nonlocality test and compared with ideal entangled coherent states. We experimentally show nearly perfect similarity with entangled coherent states for an optimal ratio of coherent and squeezed vacuum light. In our scheme, entangled coherent states are generated deterministically with small amplitudes, which could be beneficial, for example, in deterministic distribution of entanglement over long distances.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2013
In this paper, we study the interaction between a moving Λ-type three-level atom and a single-mode cavity field in the presence of intensity-dependent atom-field coupling. After obtaining the state vector of the entire system explicitly, we study the nonclassical features of the system such as quantum entanglement, position-momentum entropic squeezing, quadrature squeezing and sub-Poissonian statistics. According to the obtained numerical results we illustrate that the squeezed period, the duration of entropy squeezing and the maximal squeezing can be controlled by choosing the appropriate nonlinearity function together with entering the atomic motion effect by suitably selection of the field-mode structure parameter. Also, the atomic motion, as well as the nonlinearity function leads to the oscillatory behaviour of the degree of entanglement between the atom and field.
Multiphoton nonclassical correlations in entangled squeezed vacuum states
Physical Review A, 2013
Photon-number correlation measurements are performed on bright squeezed vacuum states using a standard Bell-test setup, and quantum correlations are observed for conjugate polarization-frequency modes. We further test the entanglement witnesses for these states and demonstrate the violation of the separability criteria, which infers that all the macroscopic Bell states, containing typically 10 6 photons per pulse, are polarization entangled. The study also reveals the symmetry of macroscopic Bell states with respect to local polarization transformations.