Excitonic magnetism at the intersection of spin-orbit coupling and crystal-field splitting

Excitonic magnetism at the intersection of spin-orbit coupling and crystal-field splitting

Blog Article

Excitonic magnetism involving superpositions of singlet and triplet states is expected to arise for two holes in strongly correlated and spin-orbit-coupled t_{2g} orbitals.However, uncontested material examples for its realization are rare.We apply the variational cluster approach to the square lattice to investigate excitonic Headband antiferromagnetism and the impact of a crystal field.

We give a phase diagram depending on spin-orbit coupling and crystal field and find excitonic magnetism to survive in the presence of substantial crystal-field-induced orbital order.We address the specific example of Ca_{2}RuO_{4} using ab initio modeling and conclude it to realize such excitonic magnetism despite its pronounced Rocker Panels/Guards/Rails orbital polarization.We also reproduce magnetic excitations and show the maximum at momentum (0,0) to be related to the excitonic character of the magnetic order.