Quasiparticle-mediated spin Hall effect in a superconductor
Source abstract
Abstract
In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin-charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Physics of Superconductivity and Magnetism · Magnetic properties of thin films · Quantum and electron transport phenomena
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (30)
Show source-provided references
1. Matsuda, Y. & Shimahara, H. Fulde–Ferrell–Larkin–Ovchinnikov state in heavy fermion superconductors. J. Phys. Soc. Jpn 76, 051005 (2007).10.1143/JPSJ.76.051005 ↗
2. Keizer, R. S. et al. A triplet supercurrent through the half-metallic ferromagnet CrO2 . Nature 439, 825–827 (2006).10.1038/nature04499 ↗
3. Khaire, T. S., Khasawneh, M. A., Pratt, W. P. Jr & Birge, N. O. Observation of spin-triplet superconductivity in Co-based Josephson junctions. Phys. Rev. Lett. 104, 137002 (2010).10.1103/PhysRevLett.104.137002 ↗
4. Robinson, J. W. A., Witt, J. D. S. & Blamire, M. G. Controlled injection of spin-triplet supercurrents into a strong ferromagnet. Science 329, 59–61 (2010).10.1126/science.1189246 ↗
5. Hubler, F., Wolf, M. J., Beckmann, D. & von Lohneysen, H. Long-range spin-polarized quasiparticle transport in mesoscopic Al superconductors with a Zeeman splitting. Phys. Rev. Lett. 109, 207001 (2012).10.1103/PhysRevLett.109.207001 ↗
6. Quay, C. H. L., Chevallier, D., Bena, C. & Aprili, M. Spin imbalance and spin-charge separation in a mesoscopic superconductor. Nature Phys. 9, 84–88 (2013).10.1038/nphys2518 ↗
7. Takahashi, S. & Maekawa, S. Spin Hall effect in superconductors. Jpn. J. Appl. Phys. 51, 010110 (2012).10.7567/JJAP.51.010110 ↗
8. Takahashi, S. & Maekawa, S. Spin current in metals and superconductors. J. Phys. Soc. Jpn 77, 031009 (2008).10.1143/JPSJ.77.031009 ↗
9. Cadden-Zimansky, P. & Chandrasekhar, V. Nonlocal correlations in normal-metal superconducting systems. Phys. Rev. Lett. 97, 237003 (2006).10.1103/PhysRevLett.97.237003 ↗
10. Cadden-Zimansky, P., Jiang, Z. & Chandrasekhar, V. Charge imbalance, crossed Andreev reflection and elastic co-tunnelling in ferromagnet/superconductor/normal-metal structures. New J. Phys. 9, 116-1-24 (2007).10.1088/1367-2630/9/5/116 ↗
11. Yamashita, T., Takahashi, S., Imamura, H. & Maekawa, S. Spin transport and relaxation in superconductors. Phys. Rev. B 65, 172509 (2002).10.1103/PhysRevB.65.172509 ↗
12. Kontani, H., Goryo, J. & Hirashima, D. S. Intrinsic spin Hall effect in the s-wave superconducting state: Analysis of the Rashba model. Phys. Rev. Lett. 102, 086602 (2009).10.1103/PhysRevLett.102.086602 ↗
13. Takahashi, S. & Maekawa, S. Hall effect induced by a spin-polarized current in superconductors. Phys. Rev. Lett. 88, 116601 (1999).10.1103/PhysRevLett.88.116601 ↗
14. Hikino, S. & Yunoki, S. Anomalous enhancement of spin Hall conductivity in a superconductor/normal-metal junction. Phys. Rev. B 84, 020512 (2011).10.1103/PhysRevB.84.020512 ↗
15. Tinkham, M. Introduction to Superconductivity 2nd edn (Dover, 2004).
16. Wakamura, T. et al. Spin injection into a superconductor with strong spin-orbit coupling. Phys. Rev. Lett. 112, 036602 (2014).10.1103/PhysRevLett.112.036602 ↗
17. Yang, H. et al. Extremely long quasiparticle spin lifetimes in superconducting aluminum using MgO tunnel spin injectors. Nature Mater. 9, 586–593 (2010).10.1038/nmat2781 ↗
18. Valenzuela, S. O. & Tinkham, M. Direct electronic measurement of the spin Hall effect. Nature 442, 176–179 (2006).10.1038/nature04937 ↗
19. Kimura, T. et al. Room-temperature reversible spin Hall effect. Phys. Rev. Lett. 98, 156601 (2007).10.1103/PhysRevLett.98.156601 ↗
20. Saitoh, E., Ueda, M., Miyajima, H. & Tatara, G. Conversion of spin current into charge current at room temperature: Inverse spin-Hall effect. Appl. Phys. Lett. 88, 182509 (2006).10.1063/1.2199473 ↗
21. Liu, L. Q. et al. Spin-torque switching with the giant spin Hall effect of tantalum. Science 336, 555–558 (2012).10.1126/science.1218197 ↗
22. Takahashi, S., Yamashita, T., Imamura, H. & Maekawa, S. Spin-relaxation and magnetoresistance in FM/SC/FM tunnel junctions. J. Magn. Magn. Mater. 240, 100–102 (2002).10.1016/S0304-8853(01)00714-4 ↗
23. Niimi, Y. et al. Giant spin Hall effect induced by skew scattering from bismuth impurities inside thin film CuBi alloys. Phys. Rev. Lett. 109, 156602 (2012).10.1103/PhysRevLett.109.156602 ↗
24. Jedema, F. J. et al. Electrical detection of spin precession in a metallic mesoscopic spin valve. Nature 416, 713–716 (2002).10.1038/416713a ↗
25. Wakamura, T., Ohnishi, K., Niimi, Y. & Otani, Y. Large spin accumulation with long spin diffusion length in Cu/MgO/Permalloy lateral spin valves. Appl. Phys. Express 4, 063002 (2011).10.1143/APEX.4.063002 ↗
26. Shoji, A., Kiryu, S. & Kohjiro, S. Superconducting properties and normal-state resistivity of single-crystal NbN films prepared by a reactive rf-magnetron sputtering method. Appl. Phys. Lett. 60, 1624–1626 (1992).10.1063/1.107220 ↗
27. Akaike, H., Funai, T., Naito, N. & Fujimaki, A. Characterization of NbN tunnel junctions with radical-nitrided AlNx barriers. IEEE Trans. Appl. Supercond. 23, 1101306 (2013).10.1109/TASC.2013.2242511 ↗
28. Niimi, Y. et al. Extrinsic spin Hall effects measured with lateral spin valve structures. Phys. Rev. B 89, 054401 (2014).10.1103/PhysRevB.89.054401 ↗
29. Arutyunov, K. Yu., Auraneva, H-P. & Vasenko, A. S. Spatially resolved measurement of nonequilibrium quasiparticle relaxation in superconducting Al. Phys. Rev. B 83, 104509 (2011).10.1103/PhysRevB.83.104509 ↗
30. Hubler, F., Lemyre, J. C., Beckmann, D. & Lohneysen, H. v. Charge imbalance in superconductors in the low-temperature limit. Phys. Rev. B 81, 184524 (2010).10.1103/PhysRevB.81.184524 ↗