Spintronics is a research field that exploits magnetic order parameters as the state variable in electronic devices, such as nonvolatile memories and logics. Spin currents play a central role in spintronics, as they can drive many key phenomena for manipulation and detection of magnetic states that associated with the electrical write-in and read-out operations. In this talk, I will show that the antiferromagnets are desirable platforms to generate unconventional spin currents. For antiferromagnets with spin-split band structures supported by symmetry, such as the noncollinear antiferromagnets Mn₃Sn and ANMn₃ (A=Ga, Ni, Sn, etc.), the transverse z-polarized spin currents are allowed and can realize the efficient deterministic switching of ferromagnets with perpendicular magnetizations, promising for conventional spintronic devices with the current in-plane (CIP) structure. In collinear antiferromagnets with strong intra-sublattice coupling (hopping), such as RuO₂ and Fe₄GeTe₂, we demonstrate that the longitudinal Néel spin currents, i.e. the staggered sublattice-resolved spin currents, can emerge and drive the giant tunneling magnetoresistance (TMR) to read-out and strong spin-transfer torque (STT) in associated current perpendicular-to-plane (CPP) antiferromagnetic tunnel junctions (AFMTJs). These unconventional spin currents in antiferromagnets open new possibilities for efficient spintronics.   

References:

[1]    Shuai Hu^#, Ding-Fu Shao^#, Huanglin Yang^#, Chang Pan^#, et al., Nat. Commun. 13, 4447 (2022).

[2]    Gautam Gurung, Ding-Fu Shao^*, and Evgeny Y. Tsymbal^*, Phys. Rev. Mater. 5, 124411 (2021).

[3]    Ding-Fu Shao, et al., Spin-neutral currents for spintronics, Nat. Commun. 12, 7061 (2021).

[4]    Ding-Fu Shao, et al., Néel Spin Currents in Antiferromagnets, arXiv:2212.02367 (2022).

 Bio: 邵定夫，研究员，博士生导师。2008年本科毕业于中国矿业大学，2013年博士毕业于中国科学院大学。2013年至2016年在中国科学院固体物理研究所担任助理研究员。2016年至2021年在美国内布拉斯加大学林肯分校访问研究，任博士后研究员、高级研究员。2021年获国家高层次人才计划资助。2021年12月全职回国，加入中国科学院合肥物质科学研究院固体物理研究所。邵定夫研究员长期从事量子材料与器件的理论研究，近期研究兴趣包括反铁磁自旋电子学、铁电材料的自旋-轨道电子学等。目前发表学术论文60余篇，其中以第一作者或通讯作者身份在Physical Review Letters、Nature Communications、Science Advances 等期刊发表论文30余篇。