Fast domain wall (DW) motion in magnetic nanostructures is crucial for future spintronic device concepts. However, a lack of energy-efficient, scalable and industry-relevant ways to electrically read and write DWs in nanoscale devices impedes practical applications. Here, we demonstrate that full electrical control of DW devices can be achieved by incorporating typical high DW velocity materials (i.e., Pt/Co and synthetic antiferromagnetic (SAF) Pt/Co/Ru/Co) into perpendicular magnetic tunnel junctions (pMTJs). We first show tunneling magnetoresistance (TMR) readout and efficient spin transfer torque (STT) writing, comparable to current STT-MRAM technology. Based on time-resolved measurements, we find faster STT switching dynamics in the SAF-based hybrid free layer than in conventional dual-MgO free layer while maintaining retention stability. We demonstrate the full operation of DW devices at nanoscale with MTJs enabling electrical read and write, and a heavy metal enabling spin orbit torque (SOT)-driven DW motion for information transmission. Beside implications to technology and applications, we show that these devices can be used as a tool to explore the physics of DW dynamics at nanoscale. Furthermore, using a SAFbased DW conduit has the potential to enhance device performance with faster and more reliable DW motion. This proof-of-concept offers a pathway to the technological development of highperformance and low-power DW-based devices.Magnetic domain walls (DW) could form a key ingredient in next generation logic and data storage devices [ 1,2] such as racetrack memory [ 3,4], spin logic [ 5,6,7,8] and neuromorphic computing [ 9,10,11].The discovery of high DW velocity governed by the Dzyaloshinskii-Moriya interaction (DMI) and spin-orbit torque (SOT) [ 12,13,14,15] in ultrathin magnetic layers on heavy metals, the additional exchange coupling torque (ECT) in synthetic antiferromagnetic (SAF) systems [ 16] and the angular momentum compensation in ferrimagnets [ 17], were major breakthroughs in the development of fast, high density, and low-energy devices based on DW motion. To enable these materials for practical application, DWs are required to be efficiently written and read at the nanoscale. However, to date, writing of DWs has mainly been performed through magnetic field-based approaches, and read out through either Hall bar devices or magnetic imaging techniques [ 5,8,9,12,13,17,14]. These schemes play a crucial role in characterizing material properties, but their applicability

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In the context of neuromorphic computation, spintronic memristors are investigated for their use as synaptic weights. In this paper, we propose and experimentally demonstrate a resistive synaptic device based on ten magnetic tunnel junctions (MTJs) connected in a serial configuration. Our device exhibits multiple resistance levels, that supports its use as a synaptic element. It allows for two operating knobs: external magnetic field and voltage pulses (Spin-Transfer Torque). Moreover, it can be operated in different ways. When varying continuously the amplitude of the voltage pulse and/or the magnetic field, eleven resistance states can be reached. In contrast, if the initial state of the chain is reset between every step, a very large number of levels are reached. Ideally, a total of 2 N resistance levels could be accessible. This coincides well with the desired analog-like behavior in ideal memristors. Since this device consists of a scalable number of N MTJs, and MTJ technology is continuously optimized and improved, the proposed memristor shows promise as a scalable synapse solution for neuromorphic hardware implementations.