Download pdf - Department of Physics, University of North Florida

Non-Cognitive Predictors of Student Success:A Predictive Validity Comparison Between Domestic and International Students


The magnetic interactions of

RuCl3 can be described through

the frustration of Heisenberg spin

exchanges


ABSTRACT: The new field of Dirac quantum matter hasproduced a lot of interesting theories andmaterials, especially in the dynamics of magneticmaterials. One such material is RuCl3, which is aS = 1/2 zigzag honeycomb lattice. Throughinelastic neutron scattering, this material hasdemonstrated spin waves with an energy scale of1.5-8.0 meV. According to literature, RuCl3 maybe the realization of a new theoretical phase ofmatter called a spin liquid. This materials seemsto fit the profile and has been investigated usinga Kitaev model. In this study, we re-examine thedata for RuCl3 using a standard Heisenberg spin-spin exchange model with easy axis anisotropy.By imposing a Holstein-Primakoff expansion andutilizing competing exchange interactions withinthe zigzag magnetic configurations of RuCl3, weprovide insight into the evolution of the spindynamics. By analyzing the system by addingfrustration, we are able to demonstrate that astandard Heisenberg model can produce anaccurate model of the observed spin waves isproduced. Therefore, with simpler modeldescribing the spin dynamics of RuCl3, weultimately shed some doubt on the currentconsiderations of RuCl3 as a quantum spin liquid.

MODEL:Using a Heisenberg spin-spin exchangeHamiltonian, we examine the spin-wavedynamics and excitations for the zig-zagmagnetic configuration of the honeycomb lattice.Using a model that incorporates variable nearestneighbor and next-nearest neighbor interactions,we investigate their effects on the overall energyand spin-wave dynamics. Through a comparisonof the various model parameters, we find that theobserved inelastic neutron scattering excitationsin RuCl3 may be a realization of spin frustrationwith spin-orbit coupling and not necessarily dueto the presence of a quantum spin liquid. Futurecalculation of the spin wave intensities willhopefully clarify this model.

E. Wilson and J. T. HaraldsenDepartment of Physics, University of North Florida, Jacksonville, Florida, USA

Take a picture to go to the UNF Materials Theory website

Understanding the magnetic interactions of the zig-zag honeycomb lattice: Application to RuCl3

K. Ran et al. Physical Review Letters 118 107203 (2017)

No Frustration Model ↓

Frustration Model ↑

Presenter

Presentation Notes

Notes: In Powerpoint, click View > Guides Keep text within gutter guides. Author list: Don’t split names onto two lines (e.g., “Jimmy [break] Smith”). If that happens, use a new line, unless you need the space. Bold the first names of anybody who’s presenting in person. Intro/methods/result: Do not drop below font size 28, but if you have extra space, jack up the font size until the space is full. Do not use color in the sidebars except in graphs/figures. It’ll pull attention from the center and slow interpretation for passersby.