Generation of Nonmaximally Entangled States Between BECs with Quantum Optimal Control Methods

In the last decade, different theoretical methods for entanglement generation between distant BEC qubits (macroscopic cold atomic ensembles) were proposed. However, experimental realization of such states is still challenging beside some special cases. The most theoretically investigated entangled states between macroscopic BECs are nonmaximally entangled states obtained with SzSz entangling Hamiltonian. With the use of such states, the protocols for quantum teleportation, remote state preporation and many others were developed for macroscopic qubits on the basis of BECs. Here we show that it is possible to obtain such states with the use of the bosonic analog of XY Hamiltonian and the methods of quantum optimal control. We compare performance of this scheme in the meaning of fidelity and entanglement for different drift and control Hamiltonians. We use the well-established QuTip open python library for all calculations.