Three-leg bosonic triangular ladder in a staggered magnetic field

Based on the dynamical Gutzwiller mean-field theory, we investigate the ground states of interacting bosons on a triangular ladder lattice, which is comprised of three legs, and in the presence of a staggered magnetic flux. As a consequence, the vortical lattice phase with triangular chiral vortical currents is discovered, which particularly features a biased ladder structure, characterized by larger populations on the inner leg than those of the two outer legs. This similar structure could be either figured out on the four-leg and five-leg flux ladders, interpreted by the Bose-Hubbard model. The variations of currents and populations induced by the growth of number of legs are discussed. We further identify a type of particle current going through a zigzag-shaped outline. It is also necessarily accompanied with the biased configuration on the distribution of population, and could be generalized to the four-leg or five-leg model.