ABSTRACT T 0.1 Significance of the Study This study provides a comprehensive theoretical and numerical investigation of light emission from a two-level atom interacting with a squeezed vacuum field. By devel oping a model based on the squeezed Jaynes–Cummings Hamiltonian and formulating atomic evolution via the master equation, the work establishes a framework for un derstanding how quantum squeezing modifies atomic dynamics. Analysis of popula tion inversion and emission characteristics shows that squeezing can enhance or inhibit spontaneous emission, accelerate population oscillations, and induce spectral narrow ing, while the second-order correlation function g(2)(τ) reveals photon antibunching and nonclassical statistics. The study further examines two-atom systems coupled to a common squeezed vacuum, highlighting steady-state entanglement and nonclassical correlations in quadrature variances, emphasizing the role of squeezing as a quantum resource. Overall, these findings provide insight into the influence of squeezed reser voirs on spontaneous emission, coherence, photon correlations, and entanglement, with important implications for quantum optics, precision spectroscopy, quantum metrology, and quantum information processing. Keywords: Master equation; Power spectrum; Quantum entanglement;Spontaneous emission; Squeezed vacuum; Two-level atom
ABSTRACT T 0.1 Significance of the Study This study provides a comprehensive theoretical and numerical investigation of light emission from a two-level atom interacting with a squeezed vacuum field. By devel oping a model based on the squeezed Jaynes–Cummings Hamiltonian and formulating atomic evolution via the master equation, the work establishes a framework for un derstanding how quantum squeezing modifies atomic dynamics. Analysis of popula tion inversion and emission characteristics shows that squeezing can enhance or inhibit spontaneous emission, accelerate population oscillations, and induce spectral narrow ing, while the second-order correlation function g(2)(τ) reveals photon antibunching and nonclassical statistics. The study further examines two-atom systems coupled to a common squeezed vacuum, highlighting steady-state entanglement and nonclassical correlations in quadrature variances, emphasizing the role of squeezing as a quantum resource. Overall, these findings provide insight into the influence of squeezed reser voirs on spontaneous emission, coherence, photon correlations, and entanglement, with important implications for quantum optics, precision spectroscopy, quantum metrology, and quantum information processing. Keywords: Master equation; Power spectrum; Quantum entanglement;Spontaneous emission; Squeezed vacuum; Two-level atom
ABSTRACT T 0.1 Significance of the Study This study provides a comprehensive theoretical and numerical investigation of light emission from a two-level atom interacting with a squeezed vacuum field. By devel oping a model based on the squeezed Jaynes–Cummings Hamiltonian and formulating atomic evolution via the master equation, the work establishes a framework for un derstanding how quantum squeezing modifies atomic dynamics. Analysis of popula tion inversion and emission characteristics shows that squeezing can enhance or inhibit spontaneous emission, accelerate population oscillations, and induce spectral narrow ing, while the second-order correlation function g(2)(τ) reveals photon antibunching and nonclassical statistics. The study further examines two-atom systems coupled to a common squeezed vacuum, highlighting steady-state entanglement and nonclassical correlations in quadrature variances, emphasizing the role of squeezing as a quantum resource. Overall, these findings provide insight into the influence of squeezed reser voirs on spontaneous emission, coherence, photon correlations, and entanglement, with important implications for quantum optics, precision spectroscopy, quantum metrology, and quantum information processing. Keywords: Master equation; Power spectrum; Quantum entanglement;Spontaneous emission; Squeezed vacuum; Two-level atom
Abstract This thesis presents an investigation into the quantum characteristics of fluorescence emitted by a two-level atom placed in the electromagnetic vacuum and driven by a classical coherent field. The theoretical analysis employs the Jaynes–Cummings model together with the master-equation formalism commonly used to describe open quantum systems. Within this framework, the work examines key nonclassical fea tures such as photon antibunching, sub-Poissonian statistics, and quantum regression. Particular emphasis is given to resonance fluorescence and the influence of weak and strong driving fields on the coherence properties of the emitted radiation. The master equation is solved in the long-time limit to obtain the evolution of relevant atomic expectation values, which are subsequently used to study population dynamics, mean photon behavior, and spectral features of the fluorescence signal. The study also highlights the role of vacuum fluctuations in spontaneous emission and their impact on the quantum behavior of the atom, ultimately providing insights into the generation of coherent and nonclassical light from driven atomic systems and their relevance to quantum communication and quantum information technologies. Keywords: Fluorescence, Jaynes–Cummings model, Photon statistics, Quantum optics, Two-level atom
Abstract This thesis presents an investigation into the quantum characteristics of fluorescence emitted by a two-level atom placed in the electromagnetic vacuum and driven by a classical coherent field. The theoretical analysis employs the Jaynes–Cummings model together with the master-equation formalism commonly used to describe open quantum systems. Within this framework, the work examines key nonclassical fea tures such as photon antibunching, sub-Poissonian statistics, and quantum regression. Particular emphasis is given to resonance fluorescence and the influence of weak and strong driving fields on the coherence properties of the emitted radiation. The master equation is solved in the long-time limit to obtain the evolution of relevant atomic expectation values, which are subsequently used to study population dynamics, mean photon behavior, and spectral features of the fluorescence signal. The study also highlights the role of vacuum fluctuations in spontaneous emission and their impact on the quantum behavior of the atom, ultimately providing insights into the generation of coherent and nonclassical light from driven atomic systems and their relevance to quantum communication and quantum information technologies. Keywords: Fluorescence, Jaynes–Cummings model, Photon statistics, Quantum optics, Two-level atom
Abstract We investigate the steady-state photon statistics and quantum properties of a cascade three-level atom coupled to a two-mode squeezed-vacuum reservoir. The mean photon number, photon-number correlations, second-order coherence, and quadrature fluctuations are examined as functions of the stimulated-emission decay constant and the squeezing parameter. The system exhibits two distinct regimes: a squeezing-dominated regime, governed by reservoir-induced correlations, and a cavity-dynamics-dominated regime, characterized by strong gain–loss competition. Enhanced squeezing increases photon generation, intermodal correlations, and intracavity energy through correlated photon-pair injection while reducing vacuum fluctuations. Conversely, stronger stimulated emission induces nonlinear amplification, asymmetric photon distributions, and sequential emission dynamics. A transition from super-Poissonian to sub-Poissonian statistics is observed, indicating the coexistence of photon antibunching and continuous-variable quantum correlations. Furthermore, atom–cavity interactions modify the generalized uncertainty bounds, revealing fundamental limitations on achievable squeezing imposed by higher-order noise processes. These findings demonstrate that engineered reservoirs and cascade atomic systems provide versatile control of nonclassical light for quantum communication, precision metrology, and continuousvariable quantum information processing.
In this paper, the quantum properties of a two-level atom interaction with squeezed vacuum reservoir is throughly analyzed. With the aid of the interaction Hamiltonian and the master equation, we obtain the time evolution of the expectation values of the atomic operators. Employing the steady-state solution of these equations, we calculate the power spectrum and the second-order correlation function for the interaction of two-level atom with squeezed vacuum reservoir. It is found that the half width of the power spectrum of the light increases with the squeeze parameter, r . Furthermore, in the absence of decay constant and interaction time, it enhances the probability for the atom to be in the upper level.
In this paper, we investigate the dynamics of fluorescent light emitted by a two-level atom interacts with squeezed vacuum reservoir is studied wisely using two-time correlation function and the master equation fundamentals approaches. We use the pertinent master equation to calculate the time-evolution of cavity filed operators as well as two-time correlation function. The mathematical analysis shows the fluorescent spectrum of light emitted by the atom is turned out to be a single peak at a Lorentz's frequency for both squeezed vacuum reservoir and thermal reservoir. On the other hand, we have identified that the squeezed vacuum reservoir input is responsible to the stimulated emission of photons from the atom. Moreover, it is identified that thermal reservoir is more efficient than squeezed vacuum reservoir to have valuable power spectrum. The power spectrum which characterizes the fluorescent light generated by a two-level atom has been summered as it is observed for both case; (i) when a two-level atom coupled to squeezed vacuum reservoir and (ii) when the two-level atom coupled to thermal reservoir. Finally, we generalized from the paper is that the power spectrum of generated light from a two-level atom coupled to thermal reservoir is greater than the power spectrum generated from a two-level atom coupled to squeezed vacuum reservoir. In contrast, more stimulated and squeezed photons are emitted in the case when the atom is coupled with squeezed vacuum reservoir.