What is it about?
Ni atoms realize a honeycomb lattice in the van der Waal quantum material NiPS3. Here, by studying a microscopic electronic model, we derive the long-sought effective Hamiltonian for the magnetic behavior of NiPS3. Using a variational scheme to solve his spin model, we found that a zig–zag antiferromagnetic order is the ground state of bulk samples in agreement with experiments. Furthermore, our results suggest that the material could manifest helical and quadrupolar orders not reported before in NiPS3.
Featured Image
Photo by Julius Drost on Unsplash
Why is it important?
Here, we report a biquadratic spin interaction in NiPS3 for the first time. This spin coupling could be instrumental for manifesting spiral magnetic orders in this van der Waals material. One aspect that has remained controversial is whether or not the zig–zag order survives up to the monolayer limit. Experiments suggest that the crystal field of bulk and monolayer NiPS3 differs; our microscopic model allows us to show that a possible consequence of that is the relative decrease in the spin couplings in monolayer systems, which shed light on the reasons behind the magnetic disorder reported in monolayer samples.
Perspectives
Working on this subject introduced me to the fascinating magnetic van der Waals materials world. I learned of the intimate connection between charge and spin and the many phenomena associated with these materials that remain to be studied. One lesson is that in systems with small spin, with bipartite lattices and where superexchange is possible, biquadratic interactions can stabilize hidden orders.
Paula Mellado
Read the Original
This page is a summary of: Spin model for the honeycomb NiPS3, Applied Physics Letters, December 2023, American Institute of Physics,
DOI: 10.1063/5.0176703.
You can read the full text:
Contributors
The following have contributed to this page
