Quantum skyrmions in two-dimensional Heisenberg ferromagnets

We study quantum-mechanical two-dimensional Heisenberg Hamiltonians containing ferromagnetic exchange interactions, a magnetic field, Dzyaloshinskii-Moriya interactions, uniaxial anisotropy and magnetic dipole interactions. Using a range of different numerical approaches, we are able to determine the phase diagram ranging from small to larger system sizes. This allows us to identify a phase hosting quantum skyrmions at intermediate magnetic fields, and we discuss its stability against perturbations like uniaxial anisotropy and dipolar interactions. Moreover, we calculate observable quantities, such as the static structure factor, as a possible experimental signature for the existence of quantum skyrmions. Finally, we predict the existence of quantum skyrmion lattices for large system sizes.