The electron resistance of a single skyrmion within ballistic approach

• Published in: Applied physics letters 2024-08, Vol.125 (7)
• Main Authors: Useinov, Artur, Raj, Ravish Kumar, Verma, Ravi Shankar, Kumar, Mohit, Kaushik, Brajesh Kumar
• Format: Article
• Language: English
• Subjects: Domain walls; Electrons; Elementary excitations; Hypothetical particles; Low voltage; Magnetoresistance; Magnetoresistivity; Particle theory; Point contact; Tunnel junctions
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0221065

An alternative way of skyrmion quasi-particle detection is simulated at low voltage bias. The point contact (PC), attached to the strip with a Néel-type skyrmion, can detect it with a higher efficiency than a magnetic tunnel junction. The method is based on detecting the skyrmion via the ballistic magnetoresistance ratio (BRR). PC's resistance with skyrmion significantly differs from the one without it. BRR is estimated in the framework of the point contact model for two directions of spin-polarized current: perpendicular to the transport direction (case 1) and along one (case 2). Skyrmion's size is assumed to be around 3.6 nm in diameter—smaller, or comparable, to the mean free path of electrons, allowing it to utilize the ballistic transport approach. As a result, resistance values for the considered Néel type skyrmion within the related size are estimated as 157 Ω for case 1 and 452.2 Ω for case 2 with optimistic BRR 101.3% and 291.7%, respectively. BRR for case 2 is higher due to the spin-filtering effect. The method also has the potential to detect the skyrmion type, or other magnetic nano structures such as bimeron, domain wall (DW), etc.