Abstract:
The controlled emergence of unconventional order in low-dimensional quantum materials is a central theme in current condensed-matter research. In this context, the air-stable van der Waals magnetic semiconductor CrSBr provides an attractive platform, combining anisotropic electronic properties with layered magnetism. Below its Néel temperature of 132 K, CrSBr exhibits A-type antiferromagnetic order, consisting of ferromagnetic layers coupled antiferromagnetically along the stacking direction [1, 2]

In this contribution, I will show how ion irradiation can be used as a tuning knob to drive and control magnetic phase transitions in CrSBr. We observe the emergence of a ferromagnetic phase from the antiferromagnetic ground state at moderate irradiation fluences, followed by its gradual suppression as disorder increases further [3, 4]. By combining structural analysis with density-functional-theory calculations, we identify irradiation-induced interstitial defects, defect-induced magnetic reconstruction, and a transition into a new crystalline phase.

These results establish defect engineering as a powerful route to manipulate symmetry-broken magnetic states in a layered quantum material. More broadly, the results demonstrate how controlled defect landscapes can be exploited to access and spatially pattern emergent magnetic phases in van der Waals quantum materials.

[1] E.J. Telford, et al. Adv. Mater., 32, 2003240 (2020).
[2] F. Long, et al. Appl. Phys. Lett. 123, 222401 (2023).
[3] F. Long, et al. Nano Lett. 23, 8468 (2023).
[4] F. Long, et al. Adv. Phys. Res., 3, 2400053 (2024). 

Resume:
周生强博士自2011年担任德国亥姆霍兹协会青年科学家研究组组长（Helmholtz Young Investigator Group Leader），2018年1月被提聘任为研究所半导体事业部的主任，工作集中在半导体材料，离子辐照材料改性、离子束分析技术，以及离子束在磁性功能材料方面的应用。获得17届国际离子束材料改性青年科学家奖，培养的博士生分别在国际半导体会议(ICPS)、磁学会议(ICM)、欧洲材料（EMRS）会议上获得青年科学家奖和最佳Poster奖。

邀请人：刘恩克（82649085，ekliu@iphy.ac.cn）