Abstract:

Ferromagnets are known to support spin-polarized currents that control various spin-dependent transport phenomena useful for spintronics. On the contrary, fully compensated antiferromagnets are long expected to be spin-independent, hindering the antiferromagnetic (AFM) spintronic applications. In contrast to this common expectation, here we show that antiferromagnets can be effectively used in spintronics, utilizing their momentum-dependence and/or sublattice-dependent spin polarization. In this talk, I will first discuss the physical mechanism of the tunneling magnetoresistance (TMR) effect in AFM tunnel junctions (AFMTJs) with collinear and noncollinear AFM electrodes, based on the understanding of the spin polarization in momentum space. Next, I will emphasize the previously overlooked sublattice-dependent spin polarization associated with the AFM-stacking in real space, such as conventional A-type and C-type stackings, and a unique X-type stacking we identified recently. These stackings support Néel spin currents, i.e., spin currents selectively flowing through different magnetic sublattices in real space, capable of driving TMR and unconventional spin torques. Our works uncover the previously unexplored potentials of antiferromagnets and pave a new route to realize spin-dependent phenomena for the efficient writing and reading of information in antiferromagnetic spintronics.

Reference:

[1]Shao and Tsymbal, Antiferromagnetic Tunnel Junctions for Spintronics, npj Spintronics 2, 13 (2024).

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

[3]Gurung, Shao et al., Nearly perfect spin polarization in noncollinear antiferromagnets, Nat. Commun. 15, 10242 (2024).

[4]Shao et al., Néel Spin Currents in Antiferromagnets, Phys. Rev. Lett. 130, 216702 (2023).

[5]Zhang, Shao et al., X-Type Antiferromagnets, arXiv: 2310.13271 (2023).

[6]Wang, Shao et al., Giant Uncompensated Magnon Spin Currents in X-type Magnets, arXiv:2502.13511 (2025). 

Biography:

Ding-Fu Shao is currently a professor at Institute of solid state physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences. He received his bachelor degree from China University of Mining and Technology in 2008, and Ph.d. from University of Chinese Academy of Sciences in 2013. He was a research assistant professor at Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences from 2013 to 2016, and then worked as a postdoc at University of Nebraska-Lincoln from 2016 to 2021. Ding-Fu’s research is focused on exploring the fundamental properties of quantum materials use first-principles calculations along with model approaches. He has published more than 70 peer-reviewed papers, including 30+ first author or corresponding author paper in high-profile journals such as Physical Review Letters, Nature Communications, Science Advances. Recent interests include the transport properties in antiferromagnetic and ferroelectric materials and their applications in electronic and spintronic devices.

Date & Time: 10:30-12:00 April 1 (Tuesday), 2025

Venue: TDLI Meeting Room N601

Tencent Meeting link: 

https://meeting.tencent.com/dm/0LDMGZhSHjxj Meeting ID: 353227149, no password