Dynamics of a multipartite hybrid quantum system with beamsplitter, dipole–dipole, and Ising interactions

Abstract

The possibility of exploiting heterogeneous quantum systems to high precision, for storing, processing, and transmitting information, makes them ideal candidates for multitasking purposes in quantum communication. Appropriate quantum systems involving a judicious choice of interactions that augment each other are potentially useful for probing deep into quantum regimes. Here, we use one such hybrid bipartite quantum model, with one subsystem made of a pair of qubits and another comprising a pair of oscillators, to study the entanglement dynamics and the entanglement transfer between discrete and continuous variables. The basic model is the standard double Jaynes–Cummings model, which, under suitable conditions, is known to support both entanglement transfer and entanglement sudden death. In this work, we generalize this model to include further experimentally relevant interactions, such as the beamsplitter-type exchange interaction between the oscillators, and dipole–dipole and Ising-type interactions between the qubits. The way various interactions and initial oscillator states affect the entanglement dynamics is examined theoretically for generic experimental conditions. Using exact analytical solutions, we show that, compared to the beamsplitter or dipole–dipole interaction, the Ising interaction can have a significant positive impact on entanglement sudden death and birth, and the postponement of the onset of these phenomena, apart from producing a substantial reduction in the time duration of the death.

The role of thermal and squeezed photons in the entanglement dynamics of the double Jaynes–Cummings model

“…So, from this analysis it can be concluded that the addition of squeezing in the system creates entanglement in atom A-field a, field a-field b subsystems and also entanglement gets transferred from atom-atom subsystem to other subsystems. In [45] and in [50], it is observed that if the field is in a coherent state, every subsystems suffers ESDs and duration of these ESDs get increased with increasing coherent photons. While, in these cases, entanglement get transferred from one subsystem to another, however, increase in coherent photons does not create new entanglement.…”

“…The entanglement dynamics of DJCM with Ising-type interaction when the field mode is either a coherent state or a thermal state is investigated in [50]. In our work, we consider a field mode which is either a squeezed coherent state or a Glauber Lachs state and do not use any approximation which consequently captures the entire dynamics of the entanglement.…”