Collective magnetic dynamics in artificial spin ice probed by ac susceptibility

Abstract

We report on the study of the thermal dynamics of square artificial spin ice, probed by means of temperature and frequency dependent AC susceptibility. Pronounced influence of the inter-island coupling strength was found on the frequency response of the samples. Through the subsequent analysis of the frequency-and coupling-dependent freezing temperatures, we discuss the phenomenological parameters obtained in the framework of Vogel-Fulcher-Tammann law in terms of the samples microscopic features. The high sensitivity and robust signal to noise ratio of AC susceptibility validates the latter as a promising and simple experimental technique for resolving the dynamics and temperature driven dynamics crossovers for the case of artificial spin ice.

The effect of confinement on thermal fluctuations in nanomagnets

“…Furthermore, it has become evident that the analogy to a point-like dipole can even be misleading, resulting in misinterpretations and quantitative discrepancies between observations and calculations. [10][11][12][13] The reason for this originates in contributions from both static and dynamic textures in the magnetization of the elements. [14][15][16][17] Even though extensive work has been done on the magnetization dynamics in such elements, [17][18][19][20] little is known about the effect of the extension of the elements on the thermal excitations.…”

“…The latter is particularly important for solving issues related to the ordering and thermal excitations of coupled mesospins. 13,[32][33][34] This knowledge may even find its application in logic and computation, 35 such as design of neuromorphic-like architectures based on ASIs and their magnonic properties. 36 See the supplementary material for the details concerning the comparison of magnon mode frequencies to analytic expressions.…”

The effect of confinement on thermally induced fluctuations in nanomagnets

“…Our work provides a theoretical and simulation approach for addressing thermal excitations in mesoscopic magnetic systems, potentially capable of further resolving their emergent collective behavior. The latter is particularly important for solving issues related to the ordering and thermal excitations of coupled mesospins [13,[29][30][31]. This knowledge may even find its application in logic and computational applications [32], such as design of neuromorphic-like architectures based on ASIs and their magnonic properties [33].…”

“…This analogy holds only to a certain extend and under specific conditions. In the case of thermal fluctuations and transitions in mesoscopic systems, it has become evident that the above description is insufficient, resulting in misinterpretations and quantitative discrepancies [10][11][12][13]. The reason for this originates in contributions from magnetization texture and fluctuations within the elements [14][15][16].…”

Magnetic-Field-Dependent Thermodynamic Properties of Square and Quadrupolar Artificial Spin Ice

“…The temperature-dependent properties of ASIs at B=0 have been explored in many prior studies [12,17,18,[30][31][32][33][34][35][36][37]. As such, Fig.…”