Quantum Information Approach to Composite Particles; Quantum Entanglement and Coherent States

Abstract

This dissertation consists of quantum correlations in composite particles composed of pairs of elementary bosons or fermions. First we discuss the composite systems in the context of quantum information theory and then make thier connection with the composite two particle systems. The main focus is on systems of two distinguishable elementary fermions, as in the case of hydrogen atom. However, composite particles of other types have also been discussed. It has been found that such systems may exhibit their composite behavior depending on how strongly correlated they are, as measured by the amount of entanglement. The role of entanglement in the description of composite particles has been explored explicitly and various bounds and limitations have been discussed. Finally, we discuss the coherent states for composite particles composed of two or more distinguishable fermions or bosons as constituent and discussed their properties such as particle counting statistics by means of Mandel’s Q-parameter.