108th CEMS Colloquium


小野 輝男 (京都大学化学研究所 教授)


2023年1月25日(水) 17:30~18:30


理化学研究所 大河内記念ホール




    Recently, I came across the term X-nics. The term was coined with the meaning of creating completely new electronics through the fusion of different fields, such as the use of new materials in integrated circuits (photonics, spintronics, topotronics, etc.) and new designs and principles (neuromorphics, etc.). In this talk, I will limit the stage to spintronics and introduce an attempt at X-spintronics, where X = antiferromagnetism, ferrimagnetism, and superconductivity.

     The development of spintronics has enabled magnetic excitation and control of magnetization by spin currents and voltage application, and magnetic memory devices based on these new technologies are already available in the market. It is natural to apply the techniques developed in ferromagnetic spintronics to antiferromagnets and ferrimagnets. Research on controlling magnetization dynamics in antiferromagnets and ferrimagnets by spin currents and voltage has been active [1,2]. The use of superconductors in spintronics has been studied in terms of spin injection, π-junction, and spin currents due to triplet cooper pairs [3]. A recent development is the discovery of the superconducting diode effect [4]. It has been proposed that the superconducting diode effect is a consequence of the helical superconducting state due to Cooper pairs with finite momentum [5-7]. In my talk, I will also introduce an example of the superconducting diode effect under zero magnetic field by breaking the time-reversal symmetry by adding magnetism to an artificial superlattice with broken inversion symmetry [8].

[1] V. Baltz, A. Manchon, M. Tsoi, T. Moriyama, T. Ono, Y. Tserkovnyak, Reviews of Modern Physics 90, 015005 (2018).
[2] S-K. Kim, G. S. D. Beach, K-J. Lee, T. Ono, T. Rasing, H. Yang, Nature Materials 21, 24 (2022).
[3] J. Linder and J. Robinson, Nature Phys. 11, 307 (2015).
[4] F. Ando et al., Nature 584, 373 (2020).
[5] A. Daido, Y. Ikeda, Y. Yanase, Phys. Rev. Lett. 128, 037001 (2022).
[6] N. F. Q. Yuana, L. Fu, PNAS 119, e2119548119 (2022).
[7] J. J. He, Y. Tanaka, N. Nagaosa, New J. Phys. 24, 053014 (2022).
[8] H. Narita et al., Nat. Nanotechnol. 17, 823 (2022).