My research is focused on the study of decoherence and quantum correlations in the context of solid state quantum computing. Currently the bulk of my studies focuses on entanglement generation between a qubit or qubits and their environment. At finite temperatures decoherence can be the result of the build up of entanglement as well as the build up of classical correlations. For interactions that lead to pure decoherence of the qubit(s), we have established that there is a direct connection between entanglement and the transfer of information about the qubit state to the environment. This distinguishes entangling from nonentangling evolutions, and allows not only the theoretical distinction between different sources of decoherence, but also for the possibility of direct measurement. The ease with which qubit-environment entanglement manifests itself physically has far reaching consequences for the operation of solid state qubits. This is because the operation of quantum algorithms on the qubits under the influence of an interaction with the environment is different for entangling and non-entangling evolutions. The study of the effects of qubit-environment entanglement is especially important in the context of solid state qubits, for which interactions with the environment are unavoidable, and the nature of the decoherence is often quantum. Modeling such decoherence without taking into account quantum effects is likely to lead to erroneous predictions for the operation of quantum computers.
