Document Type : Original Paper


Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz, Islamic Republic of Iran


The time evaluation of quantum entropy in a four-level double- type atomic system is theoretically investigated. Quantum entanglement of the atom and its spontaneous emission fields is then discussed via quantum entropy. It is found that the degree of entanglement can be increased by the quantum interference induced by spontaneous emission. The phase dependence of the atom-field entanglement is also presented.