Voltage control of magnetic monopoles in artificial spin ice

Abstract

Current research on artificial spin ice (ASI) systems has revealed unique hysteretic memory effects and mobile quasi-particle monopoles controlled by externally applied magnetic fields. Here, we numerically demonstrate a strain-mediated multiferroic approach to locally control the ASI monopoles. The magnetization of individual lattice elements is controlled by applying voltage pulses to the piezoelectric layer resulting in strain-induced magnetic precession timed for 180° reorientation. The model demonstrates localized voltage control to move the magnetic monopoles across lattice sites, in CoFeB, Ni, and FeGa based ASI's. The switching is achieved at frequencies near ferromagnetic resonance and requires energies below 620 aJ. The results demonstrate that ASI monopoles can be efficiently and locally controlled with a strainmediated multiferroic approach.

Advances in artificial spin ice

“…The magnetic state of individual nanomagnets could be read out electrically via magnetic tunnel junctions, for instance. In addition to electric currents, other stimuli that can be implemented to control the magnetic configurations include electric and magnetic fields 135 , strain 58 and heat 57 .…”

“…For neuromorphic computing, methods need to be found to mimic the spike-timing-dependent plasticity associated with neurons and, eventually, to create neural networks. For such bioinspired computation, it will be critical to implement an active or self-regulating control, for example by manipulating the magnetic state of individual nanomagnets through strain in a multiferroic composite 58 . It will also be important to be able to tune the interactions between the nanomagnets, something that is just starting to be implemented 48,49,173 and is likely to lead to new phenomena as well as new devices.…”

“…By means of careful design, it is also possible to control the emergent magnetic monopoles, which is important for device applications. For example, charge defects can be constrained to move in particular directions using certain geometries 56 or a temperature gradient 57 , and they can also be controlled by locally inducing strain with an electric field 58 . This section would not be complete without mentioning that magnetic domain walls within the nanowires constituting connected artificial spin-ice systems can also be considered as magnetic-charge carriers 59 .…”

Toroidal Order in Magnetic Metamaterials

“…Since then, the kagome and the square ice have turned out to be valuable testing grounds to model and study additional very fundamental physical phenomena. Among these are magnetic correlations, frustration and disorder 215,[273][274][275][276][277][278][279][280] , the emergence of magnetic monopoles [281][282][283][284][285][286][287][288][289][290] , the thermal relaxation behaviour [291][292][293] , phase transitions and thermal fluctuations 288,[293][294][295][296][297][298][299][300][301][302][303][304][305] , approaches for chirality control 306 and the identification of long-range order 293,[307][308][309] . Externally applied magnetic fields as well as annealing protocols have been employed to modify the magnetic configuration of these patterns 285,293,297,…”

Scientific Background

“…Since then, the kagome and the square ice have turned out to be valuable testing grounds to model and study additional very fundamental physical phenomena. Among these are magnetic correlations, frustration and disorder [193,[255][256][257][258][259][260][261][262], the emergence of magnetic monopoles [263][264][265][266][267][268][269][270][271][272], the thermal relaxation behaviour [273][274][275], phase transitions and thermal fluctuations [269,[275][276][277][278][279][280][281][282][283][284][285][286][287], approaches for chirality control [288] and the identification of long-range order [275,[289][290][291]. Externally applied magnetic fields as well as annealing protocols have been employed to modify the magnetic configuration of these patterns [266,275,278,…”