报告题目：Altermagnetism: band theory and beyond

报告人：胡仑辉  研究员（浙江大学）

报告时间：2026 年 4 月 23 日（周四）10 : 00-11 : 00

报告地点：北洋园校区 49 教 410 室

报告摘要：

       Altermagnet is a newly discovered class of collinear antiferromagnets characterized by nonrelativistic spin-split bands, opening a new frontier in quantum materials. In this talk, I will discuss two key aspects of altermagnetism. First, I will show how altermagnetism enables novel quantum phenomena: (i) the emergence of nonrelativistic spin-orbital locking/textures governed by spin group symmetry^[1]; and (ii) unique superconducting proximity effects: in nodal altermagnets, we find spin-singlet pairs with finite momentum^[2], while in nodeless altermagnets, we find a spin-polarized Josephson supercurrent^[3]. I will also show the unique layer-dependent altermagnetic even-odd effect in the KV2Se2O-family altermagnetic materials^[4], where the quasi-1D spin-split Fermi surface has been detected via the spin-selective quasi-particle interferences^[5]. Second, I will move beyond band theory to show that altermagnetic fluctuation is crucial for condensed matter theory. It completes the well-established Stoner theory of ferromagnetism^[6], and through its fluctuations, can mediate an unconventional spin-triplet superconductor, which we call inter-orbital triplet pairing^[7].

Refs:

[1] ZM Wang, et al., Spin-orbital altermagnetism, Phys. Rev. Lett. 135, 176705 (2025).

[2] SB Zhang, et al., Finite-momentum Cooper pairing in proximitized altermagnets, Nature Communications 15, 1801 (2024).

[3] C Li, et al., Spin-Polarized Josephson Supercurrent in Nodeless Altermagnets, Phys. Rev. Lett. 136, 116701 (2026).

[4] C Li, et al., Altermagnetic Even-Odd Effects in CsV2Te2O Josephson Junctions, arXiv:2602.14485 (2026).

[5] GF Yang, et al., Visualizing spin-polarization of an altermagnet KV2Se2O via spin-selective tunneling, arXiv:2603.21969 (2026).

[6] C Lu, et al., Breakdown of Stoner Ferromagnetism by Intrinsic Altermagnetism, arXiv:2510.00614 (2025).

[7] C Lu, et al., Inter-orbital spin-triplet superconductivity from altermagnetic fluctuations, arXiv:2510.19083 (2025).

报告人简介：

       Lun-Hui Hu: a Hundred-Talent-Program professor at Zhejiang University. After earning both his B.S. (2013) and Ph.D. (2018) from Zhejiang, he held post-doctoral positions at UC San Diego, Penn State, the University of Tennessee, and Aalto University. In 2023 he was selected for the National Youth Talent Program for Overseas Scholars, and last August he joined Zhejiang University. His work explores the theory of novel quantum phenomena in condensed matter, especially topological states and unconventional superconductivity & magnetism. He has published 45 papers, including first or corresponding-author publications in Nat Phys/Nat Mater(2), PRL(4), Nat Comm/Sci Adv(5), Adv Mater(1).