主讲人：罗强 副研究员（南京航空航天大学）

题 目：蜂窝晶格扩展Γ模型中的若干新奇量子态

时 间：2022年12月07日（周三）下午15：00

腾讯会议ID：555 107 055

联系人：赵继泽

摘要: Frustrated magnets with highly degenerate ground states are at the heart of hunting exotic states of matter. Recent studies in spin-orbit coupled honeycomb magnets have generated immense interest in bond-dependent interactions, appreciating a symmetric off-diagonal Γ interaction which exhibits a macroscopic degeneracy in the classical limit. In this talk, I will first give a brief review of the honeycomb Γ model, andshowthat its quantum ground state is a gapless quantum spin liquid [1]. Then, I study a generic spin model and discover a novel chiral-spin ordering with spontaneous broken time-reversal symmetry near the dominant Gamma region [2]. The chiral-spin phase is demonstrated to possess a staggered chirality relation in different sublattices, and it exhibits gapless excitations as revealed by the vanishing energy gap and the finite central charge on cylinders. Finally, I will report the occurrence of a spin-flop phase in theΓ-Γ’model in the presence of a [111] magnetic field [3].

[1] Qiang Luo, Jize Zhao, Hae-Young Kee, and Xiaoqun Wang, npj Quantum Mater. 6, 57 (2021).

[2] Qiang Luo, P. Peter Stavropoulos, J. S.Gordon, andHae-Young Kee, Phys. Rev. Res. 4, 013062 (2022).

[3] Qiang LuoandHae-Young Kee, Phys. Rev. B 105, 174435 (2022).

个人简介:

罗强，南京航空航天大学物理学院副研究员，硕士生导师。2019年博士毕业于中国人民大学，2019年-2021年在加拿大多伦多大学从事博士后研究，2021年10月至今在南航工作。主要从事凝聚态理论中新奇量子态和非常规量子临界性方面的探索，研究兴趣包括阻挫磁性、量子自旋液体和Kitaev材料等。在PRB、PRR和npj Quantum Mater.等期刊发表论文10余篇。