Relation between the entropy and the linear entropy in the ion–laser interaction
Raúl Juárez-Amaro, Leonardo Moya Rosales, Jorge Andres Anaya-Contreras, Arturo Zúñiga-Segundo, H. M. Moya-Cessa · Journal of Modern Optics · 2020
It is shown that, in the interaction of a field and a qubit, there exists a relation between the linear entropy and the von Neumann entropy. The Cayley–Hamilton theorem is used to obtain such relation. In the case we study, the qubit is given by the internal degrees of freedom of an ion trapped in a Paul trap and the field given by its external (vibrational) degrees of freedom.