Optimal route to quantum chaos in the Bose–Hubbard model

Abstract The dependence of the chaotic phase Bose–Hubbard Hamiltonian on particle number N , system size L and density is investigated in terms spectral eigenstate features. We analyse development as limit infinite Hilbert space dimension approached along different directions, show that fastest route to chaos path at fixed n ≲ 1. → ∞ constant leads a slower convergence towards random matrix theory benchmarks. In this case, from distribution generalized fractal dimensions, becomes more distinguishable for larger similar way trajectories density.