Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2011 Oct 14;107(16):167201. doi: 10.1103/PhysRevLett.107.167201. Epub 2011 Oct 11.
Artificial spin ice has become a valuable tool for understanding magnetic interactions on a microscopic level. The strength in the approach lies in the ability of a synthetic array of nanoscale magnets to mimic crystalline materials, composed of atomic magnetic moments. Unfortunately, these nanoscale magnets, patterned from metal alloys, can show substantial variation in relevant quantities such as the coercive field, with deviations up to 16%. By carefully studying the reversal process of artificial kagome ice, we can directly measure the distribution of coercivities, and, by switching from disconnected islands to a connected structure, we find that the coercivity distribution can achieve a deviation of only 3.3%. These narrow deviations should allow the observation of behavior that mimics canonical spin-ice materials more closely.
人工自旋冰已成为理解微观磁相互作用的有力工具。该方法的优势在于，由纳米级磁体组成的合成阵列可以模拟由原子磁矩组成的晶体材料。不幸的是，这些由金属合金制成的纳米级磁体在相关量（如矫顽场）上存在显著差异，最大可达 16%。通过仔细研究人工 kagome 冰的反转过程，我们可以直接测量矫顽力的分布，并且，通过将不连续的岛屿切换为连续的结构，我们发现矫顽力分布的偏差可以仅达到 3.3%。这些较小的偏差应能更精确地观察到模拟典型自旋冰材料的行为。
