Artificial Spin Ice: Designer Matter Far From Equilibrium
Lead Research Organisation:
University of Leeds
Department Name: Physics and Astronomy
Abstract
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Organisations
People |
ORCID iD |
Christopher Marrows (Principal Investigator) |
Publications
Li Y
(2017)
Thickness dependence of spin wave excitations in an artificial square spin ice-like geometry
in Journal of Applied Physics
Li Y
(2019)
Superferromagnetism and Domain-Wall Topologies in Artificial "Pinwheel" Spin Ice.
in ACS nano
Lo Conte R
(2015)
Role of B diffusion in the interfacial Dzyaloshinskii-Moriya interaction in Ta / Co 20 F e 60 B 20 / MgO nanowires
in Physical Review B
Macauley G
(2020)
Tuning magnetic order with geometry: Thermalization and defects in two-dimensional artificial spin ices
in Physical Review B
Morley S
(2017)
Vogel-Fulcher-Tammann freezing of a thermally fluctuating artificial spin ice probed by x-ray photon correlation spectroscopy
in Physical Review B
Morley S A
(2018)
Effect of FePd alloy composition on the dynamics of artificial spin ice
in Scientific Reports
Description | We have shown that thermally activated monopole motion can be imaged and that artificial spin ices show unconventional glassy freezing. We have also shown that quaiscrystalline systems show a separation into a part with a unique ground state that surrounds small regions that give rise to macroscopic degeneracy. |
Exploitation Route | We are considering neuromorphic computing as a possible application area. |
Sectors | Digital/Communication/Information Technologies (including Software) Electronics |
Title | Data associated with 'Effect of FePd alloy composition on the dynamics of artificial spin ice' |
Description | Artificial spin ices (ASI) are arrays of single domain nano-magnetic islands, arranged in geometries that give rise to frustrated magnetostatic interactions. It is possible to reach their ground state via thermal annealing. We have made square ASI using different FePd alloys to vary the magnetization via co-sputtering. From a polarized state the samples were incrementally heated and we measured the vertex population as a function of temperature using magnetic force microscopy. For the higher magnetization FePd sample, we report an onset of dynamics at $T = 493$ K, with a rapid collapse into $>90\%$ ground state vertices. In contrast, the low magnetization sample started to fluctuate at lower temperatures, $T = 393$ K and over a wider temperature range but only reached a maximum of $25\%$ of ground state vertices. These results indicate that the interaction strength, dynamic temperature range and pathways can be finely tuned using a simple co-sputtering process. In addition we have compared our experimental values of the blocking temperature to those predicted using the simple N\'{e}el-Brown two-state model and find a large discrepancy which we attribute to activation volumes much smaller than the island volume. |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |