Irreversible magnetization switching at the onset of superconductivity in a superconductor ferromagnet hybrid

• Published in: Applied physics letters 2015-12, Vol.107 (26)
• Main Authors: Curran, P. J., Kim, J., Satchell, N., Witt, J. D. S., Burnell, G., Flokstra, M. G., Lee, S. L., Cooper, J. F. K., Kinane, C. J., Langridge, S., Isidori, A., Pugach, N., Eschrig, M., Bending, S. J.
• Format: Article
• Language: English
• Subjects: Applied physics; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CRITICAL TEMPERATURE; DOMAIN STRUCTURE; Ferromagnetism; Hall probes; HYBRIDIZATION; MAGNETIC FIELDS; Magnetic switching; MAGNETIZATION; MEMORY DEVICES; Pinning; SPIN; Spin valves; SUPERCONDUCTIVITY; SUPERCONDUCTORS
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4938467

We demonstrate that the magnetic state of a superconducting spin valve, that is normally controlled with an external magnetic field, can also be manipulated by varying the temperature which increases the functionality and flexibility of such structures as switching elements. In this case, switching is driven by changes in the magnetostatic energy due to spontaneous Meissner screening currents forming in the superconductor below the critical temperature. Our scanning Hall probe measurements also reveal vortex-mediated pinning of the ferromagnetic domain structure due to the pinning of quantized stray fields in the adjacent superconductor. The ability to use temperature as well as magnetic field to control the local magnetisation structure raises the prospect of potential applications in magnetic memory devices.