Zi Yang Meng, Univ. Stuttgart.
Low-dimensional, frustrated quantum magnets exhibit a wealth of interesting phenomena, in particular, the interplay between enhanced quantum fluctuations and geometric frustration could destroy semi-classical magnetic order and drive the systems into novel quantum phases. Here we present one specific case study of the above paradigm by meanings of quantum Monte Carlo and degenerate perturbation theory. We explore ground state phase diagram and magnetic process of the spin-1/2 easy-axis Heisenberg model on the Shastry-Sutherland lattice with ferromagnetic transverse spin coupling. We find in this system a dimerized phase of triplet states, emerging out of the region at the Ising limit with extensive ground state degeneracy. The system also harbors a Neel ordered phase and a superfluid phase. The quantum phase transitions between these phases are characterized. The magnetization process exhibits plateaus at 1/3 and 1/2 of the saturated value, albeit no indications for supersolidity in this model, we find an interesting phenomenon that while the 1/3 plateau persists down to the Ising limit, the 1/2 plateau only stablizes in the quantum regime. For both plateaus, the crystalline patterns of the localized triplet excitations are determined.