Vertex dependent dynamic response of a connected Kagome artificial spin ice

Abstract

We present the dynamic response of a connected Kagome artificial spin ice with emphasis on the effect of the vertex magnetization configuration on the mode characteristics. We use broadband ferromagnetic resonance (FMR) spectroscopy and micromagnetic simulations to identify and characterize resonant modes. We find the mode frequencies of elongated, single-domain film segments not only depend on the orientation of their easy-axis with respect to the applied magnetic field, but also depend on the vertex magnetization configuration, which suggests control over the FMR mode can be accomplished by altering the vertex magnetization. Moreover, we study differences between the vertex center mode (VCM) and the localized domain wall (LDW) mode. We show that the LDW mode acts as a signature of the domain wall (DW) nucleation process and the DW dynamics active during segment reversal events. The results show the VCM and LDW modes can be controlled using a field protocol, which has important implications for applications in magnonic and spintronic devices.

Advances in Magnetics Roadmap on Spin-Wave Computing

“…The charge of these defect sites arises from the nonzero net divergence of the magnetization at the vertex, which represents a monopole-type source of magnetic fields. More important, in the context of magnonics, the vertices have recently been found to display particular high-frequency magnetic properties [242], [243].…”

Angular-dependent dynamic response and magnetization reversal in Fibonacci-distorted kagome artificial spin ice

“…We observed that the VCM exists for the applied field oriented at 𝟇 = 45 o , and is absent when 𝟇 = 15 o and 𝟇 = 30 o . We have previously shown [4] that the existence of this mode depends on two conditions: (1) At least one segment's easy axis must be in the direction of the applied DC magnetic field. mirror symmetry with respect to the 0 o axis, as does the VCM profile when the applied DC field is aligned at 0 o (see [29], Figure 8).…”

“…The forces between nearest-neighbor segments are dominated by dipolar interactions. However, exchange interactions play an important role in forming the magnetization textures near vertices in connected ASI [1][2][3][4]. The competition between magnetostatic interactions among nearest-neighbor segments leads to degenerate ground states that follow the spin ice rule (SIR) similar to the original rule observed for atomic spins in the tetrahedral sublattice of pyrochlore spin ice [5].…”

Various facets of magnetic charge correlation: Micromagnetic and distorted waveBorn approximation simulations study

“…5 The quantum mechanical properties of magnetic charge, also termed as quasi-particle, 1 enables the exploration of dynamic magnetic states in artificial Kagome ice. [11][12][13] One of such states is the quantum disordered magnetic ground state due to the competing energetics between the nearest neighbor and the next nearest neighbor exchange interactions (J 1 and J 2 , respectively). 14,15 However, the thermal tunability of lattice magnetization is necessary to the realization of such novel state, as it facilitates magnetic charge dynamics to incite a massively degenerate ground state at T → 0 K. 16 Experimental evidence to this proposition was recently obtained in a magnetic honeycomb lattice with thermally tunable characteristic, made of single domain size connecting elements.…”