nn9b05428_si_001.pdf (4.45 MB)
Stray-Field Imaging of a Chiral Artificial Spin Ice during Magnetization Reversal
journal contribution
posted on 2019-12-12, 20:19 authored by Marcus Wyss, Sebastian Gliga, Denis Vasyukov, Lorenzo Ceccarelli, Giulio Romagnoli, Jizhai Cui, Armin Kleibert, Robert L. Stamps, Martino PoggioArtificial spin ices are a class of metamaterials consisting
of
magnetostatically coupled nanomagnets. Their interactions give rise
to emergent behavior, which has the potential to be harnessed for
the creation of functional materials. Consequently, the ability to
map the stray field of such systems can be decisive for gaining an
understanding of their properties. Here, we use a scanning nanometer-scale
superconducting quantum interference device (SQUID) to image the magnetic
stray field distribution of an artificial spin ice system exhibiting
structural chirality as a function of applied magnetic fields at 4.2
K. The images reveal that the magnetostatic interaction gives rise
to a measurable bending of the magnetization at the edges of the nanomagnets.
Micromagnetic simulations predict that, owing to the structural chirality
of the system, this edge bending is asymmetric in the presence of
an external field and gives rise to a preferred direction for the
reversal of the magnetization. This effect is not captured by models
assuming a uniform magnetization. Our technique thus provides a promising
means for understanding the collective response of artificial spin
ices and their interactions.