This project focuses on the derivation of macroscopic spin Hamiltonian starting from a multiband Hubbard model in the presence of spin-orbit and Coulomb exchange interactions for novel magnetic materials. Systems of interest include frustrated quantum magnetic materials such as antiferromagnetic spins on a tetragonal lattice (i.e., SR₂CuCl₂O₂, R₂CuO₄) or Kagome lattices, as well as high-spin magnetic molecules (i.e., Fe₈ and Mn₁₂-ac). Some of the computational techniques that we use are degenerate perturbation theory, exact numerical diagonalization, 1/S expansion within interacting and non-interacting spin-wave expansion. Various magnetic properties such as ground-state spin configuration, spin dynamics due to thermal and quantum fluctuations, spin waves, and gaps, are calculated from the derived magnetic Hamiltonian and compared with the neutron scattering measurements.

 

key words

Neutron scattering; Polarization (spin alignment); Rare-earth elements; Transition metals;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants