Abstract
Artificial spin ice is made from a large array of patterned magnetic nanoislands designed to mimic naturally occurring spin ice materials. The geometrical arrangement of the kagomé lattice guarantees a frustrated arrangement of the islands’ magnetic moments at each vertex where the three magnetic nanoislands meet. This frustration leads to a highly degenerate ground state which gives rise to a finite (residual) entropy at zero temperature. In this work we use the Monte Carlo simulation to explore the effects of disorder in kagomé spin ice. Disorder is introduced to the system by randomly removing a known percentage of magnetic islands from the lattice. The behavior of the spin ice changes as the disorder increases; evident by changes to the shape and locations of the peaks in heat capacity and the residual entropy. The results are consistent with observations made in diluted physical spin ice materials.
Highlights
In spin ice pyrochlores, such as Dy2Ti2O7, the magnetic moments of the Dy3+ ions align along the tetrahedral axes of the crystal and these systems transition from ferromagnetic to antiferromagnetic spin ordering at low temperatures
Artificial spin ice is a metamaterial consisting of a patterned array of magnetic islands engineered to mimic the behavior of physical spin ice systems.[9]
The magnetic islands in artificial spin ice are single domain magnets and as such can be modeled by an Ising macrospin with a magnetic moment dependent on the material and island dimensions
Summary
Spin ice materials have garnered significant interest due to their degenerate ground state spin configurations and charge like excitations; consequences of the geometrically induced magnetic frustration imparted by the lattice.[1,2,3,4,5,6] In spin ice pyrochlores, such as Dy2Ti2O7, the magnetic moments of the Dy3+ ions align along the tetrahedral axes of the crystal and these systems transition from ferromagnetic to antiferromagnetic spin ordering at low temperatures. We model physical systems by investigating the role of disorder in kagomespin ice by randomly removing a known percentage of magnets from the full array This compares to real spin ice materials as they have been found to have nonmagnetic defects.[3,4] The removal of a single magnet at a vertex leads to local ferromagnetic coupling as the frustration is eliminated at the corresponding vertices; impacting the spin dynamics. Changing the lattice structure and geometry, as in Tetris and Shatki lattice structures, has been carried out.[18,19,20] In each case the disorder has been shown to lead to changes in the magnetization dynamics, and equilibrium states
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
