Interaction of light and semiconductor can generate quantum states required for solid-state quantum computing: entangled, steered and other nonclassical states

摘要

Proposals for solid-state quantum computing are extremely promising as they can be used to build room temperature quantum computers. If such a quantum computer is ever built, it would require built-in sources of nonclassical states required for various quantum information processing tasks. Possibilities of generation of such nonclassical states are investigated here for a physical system composed of a monochromatic light coupled to a two-band semiconductor with direct band gap. The model Hamiltonian includes both photon-exciton and exciton-exciton interactions. Time evolution of the relevant bosonic operators is obtained analytically by using a perturbative technique that provides operator solution for the coupled Heisenberg's equations of motion corresponding to the system Hamiltonian. The bosonic operators are subsequently used to study the possibilities of observing single- and two-mode squeezing and antibunching after interaction in the relevant modes of light and semiconductor. Further, entanglement between the exciton and photon modes is reported. Finally, the nonclassical effects have been studied numerically for the open quantum system scenario. In this situation, the nonlocal correlations between two modes are shown to violate EPR steering inequality. The observed nonclassical features, induced due to exciton-exciton pair interaction, can be controlled by the phase of input field, and the correlations between two modes are shown to enhance due to nonclassicality in the input field.