Magnetization Control and Transfer of Spin-Polarized Cooper Pairs into a Half-Metal Manganite
Physical Review Applied
American Physical Society
MetadataShow full item record
Srivastava, A., Olthof, L., Bernardo, A., Komori, S., Amado, M., Palomares-Garcia, C., Alidoust, M., et al. (2017). Magnetization Control and Transfer of Spin-Polarized Cooper Pairs into a Half-Metal Manganite. Physical Review Applied, 8 (4. 044008)https://doi.org/10.1103/PhysRevApplied.8.044008
The pairing state and critical temperature ( T C ) of a thin s-wave superconductor ( S ) on two or more ferromagnets ( F ) are controllable through the magnetization alignment of the F layers. Magnetization misalignment can lead to spin-polarized triplet-pair creation, and since such triplets are compatible with spin-polarized materials, they are able to pass deeply into the F layers and cause a decrease in TC. Various experiments on S/F1/F2 “triplet spin valves” have been performed with the most pronounced suppression of TC reported in devices containing the half-metal ferromagnet (HMF) CrO 2 ( F 2 ) albeit using out-of-plane magnetic fields to tune magnetic noncollinearity [Singh et al., Phys. Rev. X 5, 021019 (2015)]. Routine transfer of spin-polarized triplets to HMFs is a major goal for superconducting spintronics so as to maximize triplet-state spin polarization. However, CrO 2 is chemically unstable, and out-of-plane fields are undesirable for superconductivity. Here, we demonstrate low-field (3.3 mT) magnetization-tunable pair conversion and transfer of spin-polarized triplet pairs to the chemically stable mixed valence manganite La 2 / 3 Ca 1 / 3 MnO 3 in a pseudo-spin-valve device using in-plane magnetic fields. The results match microscopic theory and offer full control over the pairing state.
Is supplemented by: https://doi.org/10.17863/CAM.13096
This work is funded by the Royal Society (“Superconducting Spintronics”), the Leverhulme Trust (Grant No. IN-2013-033), and the EPSRC through the Programme Grant “Superspin” (Grant No. EP/N017242/1) and the “International network to explore novel superconductivity at advanced oxide superconductor/magnet interfaces and in nanodevices” Grant No. EP/P026311/1 and Doctoral Training Programme (Grant No. EP/M508007/1). J. W. A. R. and A. D. B. acknowledge support from St. John’s College, Cambridge. M. Amado acknowledges support from the European Marie Curie Action MSCAIFEF-ST No. 656485-Spin3. M. Alidoust is supported by Iran’s National Elites Foundation. K. H. is supported in part by ONR and a grant of HPC resources from the DOD HPCMP.
Royal Society (UF150676)
European Commission (656485)
Royal Society (uf100049)
External DOI: https://doi.org/10.1103/PhysRevApplied.8.044008
This record's URL: https://www.repository.cam.ac.uk/handle/1810/268080