We consider the problem of extracting a low-energy spin Hamiltonian from a triangular Kondo Lattice Model(KLM).The non-analytic dependence of the effective spin-spin interactions on the Kondo exchange excludes the use...We consider the problem of extracting a low-energy spin Hamiltonian from a triangular Kondo Lattice Model(KLM).The non-analytic dependence of the effective spin-spin interactions on the Kondo exchange excludes the use of perturbation theory beyond the second order.We then introduce a Machine Learning(ML)assisted protocol to extract effective two-and four-spin interactions.The resulting spin model reproduces the phase diagram of the original KLM as a function of magnetic field and single-ion anisotropy and reveals the effective four-spin interactions that stabilize the field-induced skyrmion crystal phase.Moreover,this model enables the computation of static and dynamical properties with a much lower numerical cost relative to the original KLM.A comparison of the dynamical spin structure factor in the fully polarized phase computed with both models reveals a good agreement for the magnon dispersion even though this information was not included in the training data set.展开更多
基金This work was supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,under Award No.DE-SC0022311Z.W.’s work at the University of Minnesota was supported by the US Department of Energy through the University of Minnesota Center for Quantum Materials under Award No.DE-SC-0016371Partial funding for open access to this research was provided by University of Tennessee’s Open Publishing Support.
文摘We consider the problem of extracting a low-energy spin Hamiltonian from a triangular Kondo Lattice Model(KLM).The non-analytic dependence of the effective spin-spin interactions on the Kondo exchange excludes the use of perturbation theory beyond the second order.We then introduce a Machine Learning(ML)assisted protocol to extract effective two-and four-spin interactions.The resulting spin model reproduces the phase diagram of the original KLM as a function of magnetic field and single-ion anisotropy and reveals the effective four-spin interactions that stabilize the field-induced skyrmion crystal phase.Moreover,this model enables the computation of static and dynamical properties with a much lower numerical cost relative to the original KLM.A comparison of the dynamical spin structure factor in the fully polarized phase computed with both models reveals a good agreement for the magnon dispersion even though this information was not included in the training data set.
