Understanding magnetotransport signatures in networks of connected permalloy nanowires

Abstract

The change in electrical resistance associated with the application of an external magnetic field is known as the magnetoresistance (MR). The measured MR is quite complex in the class of connected networks of single-domain ferromagnetic nanowires, known as 'artificial spin ice', due to the geometrically-induced collective behavior of the nanowire moments. We have conducted a thorough experimental study of the MR of a connected honeycomb artificial spin ice, and we present a simulation methodology for understanding the detailed behavior of this complex correlated magnetic system. Our results demonstrate that the behavior, even at low magnetic fields, can be well-described only by including significant contributions from the vertices at which the legs meet, opening the door to new geometrically-induced MR phenomena.

Magnetotransport in Artificial Kagome Spin Ice

“…IV, the reversal of the non-horizontal spins is a collective behavior similar to the avalanche process. Such sudden change of Hall voltage during magnetization reversal has been demonstrated experimentally[21].…”

“…The observed Hall voltage can be attributed to the anisotropic magnetore- sistance (AMR) effect. Interestingly, unlike the AMR behaviors seen in bulk ferromagnets, the field induced abrupt changes in Hall signals of artificial spin ice are related to collective many body phenomena [21]. A rather intriguing result is the observation of a large Hall voltage even at very small magnetic field.…”

“…In addition to magnetic behaviors, the magnetotransport properties of metallic kagome ice have been studied in recent experiments [4,[19][20][21][22]. The observed Hall voltage can be attributed to the anisotropic magnetore- sistance (AMR) effect.…”

Colloquium : Ice rule and emergent frustration in particle ice and beyond

“…1(b,c). Soon, a growing number of groups began using ASI to investigate topological defects, the dynamics of magnetic charges, and spin fragmentation Ladak et al, 2011aLadak et al, ,b, 2010Mengotti et al, 2011;Phatak et al, 2011;Pollard et al, 2012;Rougemaille et al, 2011;Zeissler et al, 2013), as well as information encoding (Wan, 2016;Lammert et al, 2010), equilibrium and nonequilibrium thermodynamics (Budrikis et al, 2013(Budrikis et al, , 2011Chioar et al, 2014a,a;Cugliandolo, 2017;Ke et al, 2008;Lammert et al, 2012;Levis et al, 2013;Morgan et al, 2011;Nisoli et al, 2010Nisoli et al, , 2007, avalanches (Hügli et al, 2012;Shen et al, 2011), direct realizations of the Ising system (Arnalds et al, 2016;Chioar et al, 2016Chioar et al, , 2014bNisoli, 2016;Zhang et al, 2012), magnetoresistance and the Hall effect (Branford et al, 2012;Le et al, 2017), critical slowing down (Anghinolfi et al, 2015), dislocations (Drisko et al, 2017), spin wave excitations (Gliga et al, 2013), ratchet effects (Gliga et al, 2017), dimensionality reduction (Gilbert et al, 2016a), classical topological states (Gilbert et al, 2014;Lao et al, 2018;Perrin et al, 2016), quasi-crystals (Barr...…”

Magnetization reversal in kagome artificial spin ice studied by first-order reversal curves

“…In the spin ice structures, the magnetization reversal is usually controlled by the ice rule that governs the number of magnetizations pointing into and out of each vertex to minimize the local magnetostatic energy [8,13]. The magnetization reversal process in the spin ice structures has been systematically studied by real-space imaging techniques [7][8][9][15][16][17][18], magnetic hysteresis loop measurements using the magneto-optic Kerr effect [19 , 20 ] , and magnetoresistance (MR) measurements [16,[21][22][23]. The correlation between the magnetization switching and the associated MR change during the reversal process was carefully investigated recently [23].…”