Designing Hysteresis with Dipolar Chains

Abstract

Materials that have hysteretic response to an external field are essential in modern information storage and processing technologies. A myriad of magnetization curves of several natural and artificial materials have previously been measured and each has found a particular mechanism that accounts for it. However, a phenomenological model that captures all the hysteresis loops and at the same time provides a simple way to design the magnetic response of a material while remaining minimal is missing. Here, we propose and experimentally demonstrate an elementary method to engineer hysteresis loops in metamaterials built out of dipolar chains. We show that by tuning the interactions of the system and its geometry we can shape the hysteresis loop which allows for the design of the softness of a magnetic material at will. Additionally, this mechanism allows for the control of the number of loops aimed to realize multiple-valued logic technologies. Our findings pave the way for the rational design of hysteretical responses in a variety of physical systems such as dipolar cold atoms, ferroelectrics, or artificial magnetic lattices, among others.

Self-organization into ferroelectric and antiferroelectric crystals via the interplay between particle shape and dipolar interaction

“…1 A-D). In relation to this, it is worth noting that even in simple dipolar systems an interesting hysteretic response is observed under a specially designed arrangement of dipoles (47). In this article, we show a simple physical principle, by which we are able to control the tendency toward ferroelectric or antiferroelectric ordering, and discuss its relevance to material design.…”

Bioinspired magnetic active matter and the physical limits of magnetotaxis

“…The existence and evolution of these structures at different length scales are intimately tied to the type of interactions between their basic constituents, particle symmetries, and emergent symmetries that may show up due to interactions [22][23][24]. For [13,14] having two magnetic charges +Q, −Q at the poles of the rod, where Q = M s πr 2 . Their north and south poles are highlighted in red and blue, respectively.…”

“…Thus, we have built a set of active agents that interact via a magnetic field, and hard-core interactions. We emphasize that in this work the size of magnet is not small compared with the size of the object, making it mandatory to adopt a dumbbell model instead of a point-like dipole [14,[46][47][48][49][50][51].…”

“…3 and Supplementary Information). In this description, inertial magnets interact through the full long-range Coulomb potential in the dumbbell approach [14,[46][47][48][49][50][51].…”

“…Each cylindrical magnet shown has radius r = 1.5875 × 10 −3 m, and saturation magnetization M s = 1.1 × 10 6 A/m (See Supplementary Material S5). (d) In MAM each dipole is modeled as a magnetic dumbbell[13,14] having two magnetic charges +Q, −Q at the poles of the rod, where…”