Efficient Langevin simulation of coupled classical fields and fermions

We introduce an efficient Langevin method to study bilinear fermionic Hamiltonians interacting with classical fields. Our approach is orders of magnitude faster than previous methods when applied to very large systems with high accuracy requirements. To demonstrate the method, we study complex noncoplanar chiral spin textures on the triangular Kondo lattice model. We also explore nonequilibrium mesoscale physics such as chiral domain coarsening and Z₂ vortex annihilation.