An improved variational ansatz is proposed to capture the most strikingproperties of the ground state of a slightly biased attractive two-siteBose-Hubbard Hamiltonian. Our ansatz, albeit its simplicity, is found tocapture well the exact properties of the ground state for a wide variety ofmodel parameters, in particular the fragmentation occurring before theformation of cat-like states and also the formation of strongly correlatedcat-like states.
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