Quantum Gutzwiller approach for the two-component Bose-Hubbard model

We study the effects of quantum fluctuations in two-component Bose-Hubbard model generalizing to mixtures Gutzwiller approach introduced recently [Phys. Rev. Research 2, 033276 (2020)]. As a basis for our study, we analyze mean-field ground-state phase diagram and spectrum elementary excitations, with particular emphasis on transitions model. Within critical regimes, address both superfluid transport properties linear response dynamics density spin probes direct experimental relevance. Crucially, find that have dramatic effect drag between species system, particularly vicinity paired antipaired phases absent usual one-component Additionally, analyse contributions corrections one-body coherence density/spin from perspective collective modes providing results few-body correlations all regimes diagram.