Fig. 2: State-space representations and transport equations of spintronic memristors.

a Schematic of a magnetic tunnel junction (MTJ) as a typical example for nanomagnet/macrospin systems and detection of magnetization using the tunnel magnetoresistance effect. b Experimental result of current-induced binary switching in a perpendicular MTJ. c Schematic of multi-domain magnet /nanomagnet ensemble systems with coupled magnetization states in a heavy metal/ferromagnet bilayer and detection of overall magnetization using the anomalous Hall effect. d Experimental result of current-induced analog resistance switching in an antiferromagnet/ ferromagnet heterostructure. e Schematic of a Néel-type domain wall and detection of magnetization map using magneto-optical Kerr effect (MOKE). f Experimental observation of a domain wall and the current-driven domain wall motion in a racetrack using MOKE. g Schematic of a Néel-type skyrmion and its detection using transmission X-ray microscopy (TXM). h Experimental observation of skyrmions and the current-driven skyrmion motion in a racetrack using scanning TXM. i Schematic of spin waves and their excitation and detection using microwave antenna. The spin waves can be spatially and temporally resolved using Brillouin light scattering (BLS). j Micro-focused BLS microscope image of a standing spin wave (upper panel), where amplitude and phase of spin waves are shown (lower panel). Part (b) reprinted with permission from ref. ⁷⁰, Springer Nature Limited. Part (d) reprinted with permission from ref. ⁷⁵, Springer Nature Limited. Part (f) reprinted with permission from ref. ³⁸, Springer Nature Limited. Part (h) reprinted with permission from ref. ⁸⁹, Springer Nature Limited. Part (j) adapted with permission from ref. ¹⁰¹, Copyright © 2015 Sebastian, Schultheiss, Obry, Hillebrands and Schultheiss.