Interaction of Non-classical States With Simple Atomic Systems

with Reeta Vyas

My primary research interests are in studying the fundamental nature of light and how it interacts with atoms. Light beams produced by an incandescent bulb, a laser, and an atom are different. An understanding of this difference requires the use of quantum theory. According to quantum theory light exhibits both wave-like and particle-like behaviors and its interaction with atoms cannot be understood without incorporating both aspects.

The undergraduate summer research will be part of our research program to study the properties of non-classical states and their interaction with simple atomic systems consisting of two- and three-level atoms. The atom can be in free space or inside an optical cavity. In both cases we will include dissipation due to atomic and cavity decays. We will consider nonclassical states generated by nonlinear optical systems such as parametric oscillators. Many of these states have been experimentally realized. This has opened exciting possibilities for precision measurements and study of novel phenomena in the interaction of atoms and light. The introduction of nonclassical light in the model will allow us to explore regimes, which from the start have no classical analogs. The research will focus on the quantum nature of the atom-field interaction and how it is reflected in the fluctuation and correlation properties of the emitted fields.

We are also investigating coherence and noise properties of light emitted by semiconductor microcavity and coupled quantum dots. Various observable quantities such as coherence, intensity correlation, moments, photon statistics, and photoelectric current spectra will be calculated. Dependence of these quantities on microcavities parameters and signature of quantum nature of light will be explored. These studies of coherence and noise will also provide important pointers for improving performance of microcavity systems.

Another project is on polarization and angular momentum properties of the Maxwell-Gaussian beams. Linearly polarized laser beams are usually modeled as scalar solutions of the paraxial wave equation multiplied by a constant unit polarization vector. This provides an adequate description of laser beams for many purposes. But these solutions do not describe the polarization and focusing properties correctly. Maxwell's equations require that a linearly polarized light beam of finite cross section must be accompanied by small longitudinal polarization and cross polarization components. The project will be to investigate properties of cross polarization components of higher order Maxwell-Gaussian beams.

The undergraduate student will work on one of the above mentioned projects and will involve in developing theoretical models, performing analytic calculations, and computer simulations. We are following both analytical and computer simulation approach. Student will have opportunities to learn about random number generator, computer programming (Mathematica, Maple, C++ or fortran), and numerical techniques. This project will provide a good training in numerical methods, computer simulations, statistical methods, which can be useful in many other areas of science, social science and even stock market.