Frequency variations in impulse excitations as a way of entanglement increase in the two-mode Bose–Hubbard model

Abstract

A system of two coupled quantum oscillators in the Bose–Hubbard model is discussed as a source of maximally entangled states obtained by ultrashort coherent pulses. Both oscillators are externally driven, and by appropriate relations between the frequencies, we can manipulate the degree of entanglement in bosonic modes. Created entanglement between two subsystems can be controlled and depends strictly on the number of pulses applied to one of the coupler’s parts during a unitary evolution of the other. It is shown that the creation of maximally entangled states is possible, especially for cases when applying other types of excitations (continuous driving or simultaneous excitations) leads to a very weak entanglement of the coupled bosonic system.