Defect-implantation for the all-electrical detection of non-collinear spin-textures

Abstract

The viability of past, current and future devices for information technology hinges on their sensitivity to the presence of impurities. The latter can reshape extrinsic Hall effects or the efficiency of magnetoresistance effects, essential for spintronics, and lead to resistivity anomalies, the so-called Kondo effect. Here, we demonstrate that atomic defects enable highly efficient all-electrical detection of spin-swirling textures, in particular magnetic skyrmions, which are promising bit candidates in future spintronics devices. The concomitant impurity-driven alteration of the electronic structure and magnetic non-collinearity gives rise to a new spin-mixing magnetoresistance (XMR defect). Taking advantage of the impuritiesinduced amplification of the bare transport signal, which depends on their chemical nature, a defect-enhanced XMR (DXMR) is proposed. Both XMR modes are systematised for 3d and 4d transition metal defects implanted at the vicinity of skyrmions generated in PdFe bilayer deposited on Ir(111). The ineluctability of impurities in devices promotes the implementation of defect-enabled XMR modes in reading architectures with immediate implications in magnetic storage technologies.

Sub-nanoscale atom-by-atom crafting of skyrmion-defect interaction profiles

“…The adatoms are relaxed by 18% similarly to what was considered in Ref. 40 . To extract the tensorial exchange coupling, one single interation Figure 7.…”

“…The adatoms are relaxed by 18% similarly to what was considered in Ref. 40 . To extract the tensorial exchange coupling, one single interation was performed using the infinitesimal rotation method 66 – 68 considering a k-mesh of and an angular momentum cut-off at .…”

“…In tandem to the few available experiments, scarce ab-initio simulations addressed the case of point-defects 34 , 36 , 39 , 40 while several phenomenological-based studies were dedicated to various defects assuming local changes in the magnetic properties of the material 3 , 28 , 29 , 33 , 35 , 41 – 48 . Yet, the energy-landscape impacting skyrmions as induced by complex defects remains weakly explored.…”

Emergence of zero-field non-synthetic single and catenated antiferromagnetic skyrmions in thin films

“…They often result from the competition between the Heisenberg exchange and the relativistic Dzyaloshinskii-Moriya interaction (DMI) 13,14 , which is present in materials, that lack inversion symmetry and have a finite spin orbit coupling. Since their discovery in multiple systems, ranging from bulk, thin films, surfaces to multilayers [15][16][17][18][19][20][21][22][23] , skyrmions are envisioned as promising candidates for bits, potentially usable in the transmission and storage of information in the next generation of spintronic devices [24][25][26][27][28][29] . However, requirements for future (nano-)technologies are not only limited to the generation of information bits but are also highly stringent from the point of view of simultaneous efficiency in reading, control, and power consumption 28,30 .…”

Friedel oscillations induced by magnetic skyrmions: from scattering properties to all-electrical detection

“…1). Since skyrmions are heavily prospected as potential magnetic bits for future devices [26][27][28][29][30][31][32][33][34][35], the induced Friedel oscillations could bear interesting information on the nature of the skyrmions and their interaction with the surrounding, which could prove useful for applications. The classical example of a storage device based on skyrmions is a racetrack memory [26,28,36], where the magnetic textures would be driven by a current.…”