Thermally superactive nanomagnets obtained with interfacial Dzyaloshinskii-Moriya interaction

The lowest achievable blocking temperature limits magnetic ordering in highly frustrated thermally active artificial kagome spin ice. By exploiting the interfacial Dzyaloshinskii-Moriya interaction, we can lower the blocking temperature of individual nanomagnets without strongly affecting their magnetic moments, thus leaving the critical transition temperatures unchanged. Using this approach, we demonstrate that a seven-ring kagome structure consisting of 30 nanomagnets can be thermally annealed into its ground state. Furthermore, the spin-ice correlations extracted from extended kagome lattices are found to exhibit the quantitative signatures of long-range charge-order, thereby giving experimental evidence for the theoretically predicted continuous transition to a charge-ordered state.