Magnetic skyrmions are topologically stabilized quasiparticles and are promising candidates for energy-efficient applications, such as storage but also logic and sensing devices. Here we present a concept for a multiturn counter-sensor device based on skyrmions, where the number of sensed rotations is encoded in the number of nucleated skyrmions. The skyrmion-boundary force in the confined geometry of the device in combination with the topology-dependent dynamics leads to the effect of automotion for certain geometries. For our case, we describe and investigate this effect with micromagnetic simulations and the Thiele equation in a triangular geometry with an attached reservoir as part of the counter-sensor device. We explore the device functionality, taking into account the influence of thermal diffusion. Additionally, we analyze a readout mechanism for the skyrmion storage, capable of quantifying skyrmion numbers and working effectively even in the presence of thermal diffusion. Finally, our investigation studies the deterministic nucleation of skyrmions.

• Received 9 November 2022
• Revised 2 October 2023
• Accepted 15 November 2023

DOI:https://doi.org/10.1103/PhysRevApplied.20.064021