I= EFFECT OF THE DYNAMIC SHIFT ON THE QUANTUM ELECTRODYNAMICS OF AN ATOM MAKING TWO-PHOTONS IN AN IDEAL CAVITY
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Title of Thesis
EFFECT OF THE DYNAMIC SHIFT ON THE QUANTUM ELECTRODYNAMICS OF AN ATOM MAKING TWO-PHOTONS IN AN IDEAL CAVITY

Author(s)
TAHIRA NASREEN
Institute/University/Department Details
Department of Physics/ Quaid-e-Azam University Islamabad, Pakistan
Session
1992
Subject
Physics
Number of Pages
192
Keywords (Extracted from title, table of contents and abstract of thesis)
dynamic shift, quantum electrodynamics, ideal cavity, dynamical stark shift, photon transitions, quantized radiation field, nondegenerate two-photon jaynes-cummings model, ntpjcm, two-photon processes, two-photon effective hamiltonian, emission spectra, cavity field spectrum, field wave function

Abstract
In this thesis, we investigate the effect of the dynamical Stark shift on the quantum electrodynamics of an atom undergoing two-photon transitions, interacting with a quantized radiation field in an ideal cavity. To begin with, we discuss the dynamics of the electromagnetic field and the atom in the presence of the Stark shift. We derive closed expressions for the second-order coherence function, quadrature variances, atomic population inversion and dipole squeezing under the approximation of a large initial photon number and coherent or squeezed field input. We show that for an atom initially in the ground state, the inclusion of Stark shift reduces the field squeezing as well as the antibunching. Both the population inversion and the dipole squeezing exhibit phase sensitivity in the presence of Stark shift and for a particular choice of the relative phase of the two atomic levels "trapping" occurs in a two-level atom and the dipole is modified in such a way that it is permanently squeezed. We then discuss the effect of the stark shift on the emission spectrum of an atom and the cavity field spectrum. The inclusion of Stark shift results in asymmetric vacuum field Rabi splitting. We also study the dynamics of the combined atom-field wave function in the presence of the Stark shift and show that both the electromagnetic field and the atom periodically evolve to pure states which are radically different from those in the absence of the Stark shift. Finally, we study the nondegenerate two-photon Jaynes-Cummings model (NTPJCM) in the presence of the Stark shift and show that the dynamics of the NTPJCM in the presence of Stark shift is qualitatively different from the case of the absence of the Stark shift and radically different from the case of degenerate two-photon JCM in the presence of Stark shift.

Download Full Thesis
4157.97 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
178.43 KB
2 1 Introduction
2448.71 KB
  1.1 Two-photon Processes 1
  1.2 Degenerate Two-Photon Effective Hamiltonian in the Presence of Stark Shift 3
  1.3 Nondegenerate Two-Photon Effective Hamiltonian in the Presence of the Stark Shift 6
  1.4 Organization of the Thesis 9
3 2 Dynamics Of The Field
402.35 KB
  2.1 Introduction 13
  2.2 Two-Photon Jaynes -Cummings Model in the Presence of Stark Shift 15
  2.3 Evolution of the Density Matrix 21
  2.4 Second-Order Coherence Function 27
  2.5 Squeezing of the Radiation Field 42
  2.6 Conclusions 55
4 3 Dynamics Of The Atom
428.98 KB
  3.1 Introduction 57
  3.2 Expectation Values of the Atomic Operators 61
  3.3 Population Inversion 68
  3.4 Atomic Dipole Squeezing 78
  3.5 Conclusions 92
5 4 Spectral Properties Of The Atom And The Field
339.89 KB
  4.1 Introduction 94
  4.2 The Emission Spectra of the Atom 95
  4.3 Cavity Field Spectrum 114
  4.4 Conclusions 128
6 5 Evolution Of Wave Function
276.45 KB
  5.1 Introduction 130
  5.2 Coupled Atom-Field Wave Function 132
  5.3 Evolution of the Wave Function In the absence of Stark Shift 134
  5.4 Evaluation of the Wave Function in the presence of Stark Shift 147
  5.5 Conclusions 156
7 6 Dynamics Of Nondegenerate Two-Photon JCM
327.61 KB
  6.1 Introduction 158
  6.2 Model and System of Equations 160
  6.3 Atomic Dipole Squeezing 166
  6.4 The Emission Spectra of the Atom 173
  6.5 Conclusions 184
  6.6 Refrences 185