Sculpting the spin-wave response of artificial spin ice via microstate selection

Artificial spin ice (ASI) systems have emerged as promising hosts for magnonic applications due to a correspondence between their magnetic configuration and spin dynamics. Though it has been demonstrated that spin-wave spectra are influenced by the ASI microstate the precise nature of this relationship has remained unclear. Recent advances in controlling the magnetic configuration of ASI make harnessing the interplay between spin dynamics and the microstate achievable. This could allow diverse applications including reconfigurable magnonic crystals and programmable microwave filters. However, extracting any novel functionality requires a full understanding of the underlying spin-wave/microstate interaction. Here, we present a systematic analysis of how the microstate of a honeycomb ASI system affects its spin-wave spectrum through micromagnetic simulations. We find the spectrum to be highly tunable via the magnetic microstate, allowing the (de)activation of spin-wave modes and band-gap tuning via magnetic reversal of individual nanoislands. Symmetries of ASI systems and the chirality of "monopole" defects are found to play important roles in determining the high-frequency magnetic response.

人工自旋冰（ASI）系统由于其磁构型和自旋动力学之间的对应关系，已成为磁振子应用的有前景的载体。尽管已经证明自旋波谱受ASI微观态的影响，但这种关系的确切性质仍不清楚。在控制ASI磁构型方面的最新进展使得利用自旋动力学和微观态之间的相互作用成为可能。这可能允许多种应用，包括可重构的磁振子晶体和可编程的微波滤波器。然而，提取任何新的功能都需要对潜在的自旋波/微观态相互作用有充分的了解。在此，我们通过微磁模拟对蜂窝状ASI系统的微观态如何影响其自旋波谱进行了系统分析。我们发现通过磁微观态，谱具有高度可调性，允许通过单个纳米岛的磁反转来激活/去激活自旋波模式以及调节带隙。发现ASI系统的对称性和“磁单极子”缺陷的手性在决定高频磁响应方面起着重要作用。