Entanglement of Two Coupled Atoms in the Presence of a Time-Dependent External Magnetic Field

Abstract

We study the problem of a time-dependent nonuniform magnetic field in the Heisenberg chain. We consider two cases: a single two-level atom and N-level atoms affecting by the magnetic field. We obtain the wave function and use it for calculating the expectation values of the dynamical operators, more precisely, the atomic inversion, in order to study the phenomena of revivals and collapses. Furthermore, we obtain the expectation value of other operators of the SU(2) group and discuss the phenomenon of squeezing. We show that the phase angle η and the detuning parameter δ are the most substantial parameters of the model under consideration.