Exploring dynamical modes in tilted square artificial spin ice*

Artificial Spin ices (ASIs) are periodic arrays of interacting nanomagnets exhibiting geometric frustration [1]. Due to their periodic nature, ASIs can be viewed as magnonic crystals [2], exhibiting reconfigurable magnon modes [3] and band structures [4] depending on the magnetization state. A new frontier is the exploration of ASIs in three-dimensional geometries [5]. Here, we use Gænice [6], a novel semi-analytical code for arbitrary artificial spin ices, to investigate the frequency response of a square ASI geometry with nanomagnets tilted out of the x-y plane and keeping the center-to-center distance between nanomagnets constant. In our study, we investigated both vortex and remanent states. For both states, we found a redshift for the high-frequency modes. Low-frequency modes emerged at critical tilt angles of 30 deg and 78 deg in the vortex state and 25 deg and 41 deg for the remanent state. Micromagnetic simulations recover these two features and quantitatively agree with the predictions done by Gænice. Our results pave the way to explore dynamical modes in the realm of 3D ASI geometries.

References:

[1] S. H. Skjærvø et al., Nat. Rev. Phys. 2, 13 – 28 (2020)

[2] S. Gliga, E. Iacocca, and O. G. Heinonen, APL Materials 8, 040911 (2020)

[3] S. Lendinez and M. B. Jungfleisch, J. Phys.: Condens. Matter 32, 013001 (2019)

[4] E. Iacocca et al., Phys. Rev. B 93, 134420 (2016); T. D. Lasnier and G. M. Wysin, Phys. Rev. B 101, 224428 (2020)

[5] A. May, M. Saccone, A. van den Berg, J. Askey, M. Hunt, and S. Ladak, Nature Communications 12, 3217 (2021)

[6] G. Alatteili et al., arXiv:2309.03826