Maple leaf antiferromagnet in a magnetic field
Pratyay Ghosh, Jannis Seufert, Tobias Müller, Frédéric Mila, Ronny Thomale
Abstract
We analyze the quantum antiferromagnet on the maple leaf lattice in the presence of a magnetic field. Starting from its exact dimer ground state and for a magnetic field strength of the order of the local dimer spin-exchange coupling, we perform a strong-coupling expansion and extract an effective hard-core boson model. The interplay of effective many-body interactions, suppressed single-particle dynamics, and correlated hopping gives way to an intriguing series of superfluid to insulator transitions which correspond to magnetization plateaus in terms of the maple leaf spin degrees of freedom. While we find plateaus at intermediate magnetization to be dominated by bosonic density wave order, we conjecture plateau formation from multiboson bound states due to correlated hopping for lower magnetization.