於國強

從事自旋電子學(同時利用電子的自旋和電荷屬性)材料和器件相關的研究。致力於探索磁性薄膜異質結材料與器件中自旋軌道耦合相關的物理效應及其在磁存儲、磁邏輯方面的應用。目標是開發出具有高性能和高能源效率的新型自旋電子學器件。 ^[1] 

近幾年來重點研究磁性薄膜異質結材料和器件中的自旋軌道力矩和室温拓撲磁性斯格明子，獲得了多項重要科研成果。至今已經在Nat. Nanotech. (2篇)、Nat. Mater. (2篇)、Nat. Phys. (1篇)、Nat. Electron. (3篇)、Nat. Commun. (5篇)、Science (1篇)、Sci. Adv. (2篇)、Adv. Mater. (6篇)、Adv. Funct. Mater. (3篇)、Nano Lett. (9篇)、Phys. Rev. Lett. (8篇)等國際重要期刊上發表學術論文100餘篇，引用超過7000餘次。 ^[1] 

(1) Jinwu Wei, Xiao Wang, Baoshan Cui, Chenyang Guo, Hongjun Xu, Yao Guang, Yuqiang Wang, Xuming Luo, Caihua Wan, Jiafeng Feng, Hongxiang Wei, Gen Yin, Xiufeng Han*, Guoqiang Yu* “Field-Free Spin–Orbit Torque Switching in Perpendicularly Magnetized Synthetic Antiferromagnets” Advanced Functional Materials 32, 2109455 (2021)[利用層間耦合作用，實現了零外磁場條件下自旋軌道矩驅動垂直人工反鐵磁磁矩翻轉。]

(2) Jinwu Wei, Hai Zhong, Jiuzhao Liu, Xiao Wang, Fanqi Meng, Hongjun Xu, Yizhou Liu, Xin Luo, Qinghua Zhang, Yao Guang, Jiafeng Feng, Jia Zhang, Lihong Yang, Chen Ge*, Lin Gu, Kuijuan Jin, Guoqiang Yu*, Xiufeng Han “Enhancement of Spin-Orbit Torque by Strain Engineering in SrRuO₃ Films” Advanced Functional Materials 31, 2100380 (2021) [發現室温下SrRuO₃誘導產生的自旋軌道矩與結構和應變相關，通過調控結構和應力將自旋軌道矩效率提高20倍。]

(3) H. Xu, J. Wei, H. Zhou, J. Feng, T. Xu, H. Du, C. He, Y. Huang, J. Zhang, Y. Liu, H. Wu, C. Guo, X. Wang, Y. Guang, H. Wei, Y. Peng, W. Jiang, G. Q. Yu*, X. Han “High Spin Hall Conductivity in Large-Area Type-II Dirac Semimetal PtTe₂” Advanced Materials 32, 2000513 (2020) [成功製備了大面積、高質量、厚度可控的第二類狄拉克半金屬PtTe₂薄膜，證實了其具有非常大的自旋軌道力矩效應，自旋霍爾電導為範德瓦爾斯材料的紀錄值。]

(4) X. Wang#, J. Tang#, X. Xia#, C. He, J. Zhang, Y. Liu, C. Wan, C. Fang, C. Guo, W. Yang, Y. Guang, X. Zhang, H. Xu, J. Wei, M. Liao, X. Lu, J. Feng, X. Li, Y. Peng, H. Wei, R.Yang, D. Shi, X. Zhang, Z. Han*, Z. Zhang, G. Zhang*, G. Q. Yu* and X. Han “Current-driven magnetization switching in a van der Waals ferromagnet Fe₃GeTe₂” Science Advances 5, eaaw8904 (2019); 引用次數：100次 [實驗證明了，可以利用自旋霍爾效應產生的自旋極化電流操控二維磁性材料Fe₃GeTe₂的磁矩。]

(5) Q. Shao#, C. Tang#, G. Q. Yu*, A. Navabi, H. Wu, C. He, J. Li, P. Upadhyaya, P. Zhang, S. A. Razavi, Q. L. He, Y. Liu, P. Yang, S. K. Kim, C. Zheng, Y. Liu, L. Pan, R. K Lake, X. Han, Y. Tserkovnyak, J. Shi, K. L. Wang* “Role of dimensional crossover on spin-orbit torque efficiency in magnetic insulator thin films” Nature Communications 9, 3612 (2018) [實驗證明，電流在無法通過磁性絕緣體的情況下仍然可以通過自旋軌道力矩驅動其磁矩翻轉，並證明了自旋軌道力矩與鐵磁層磁化強度的相關性。]

(6) Q. Shao#*, G. Q. Yu#*, Y. Lan#, Y. Shi, M. Li, C. Zheng, X. Zhu, L. Li, P. Amiri, K. L. Wang* "Strong Rashba-Edelstein Effect-Induced Spin-Orbit Torques in Monolayer Transition Metal Dichalcogenides/Ferromagnet Bilayers" Nano Letters 16 (12), pp 7514–7520 (2016) 引用次數：200次 [在可大規模生產的單層過渡金屬硫化物/磁性薄膜複合結構中，發現了一個由Rashba效應導致產生的自旋軌道力矩，揭示了二維過渡金屬硫化物作為自旋軌道力矩材料的潛力。]

(7) G. Q. Yu#*, P. Upadhyaya#, Y. B. Fan, J. G. Alzate, W. J. Jiang, K. L Wong, S. Takei, S. A. Bender, L. T. Chang, Y. Jiang, M. R. Lang, J. S. Tang, Y. Wang, Y. Tserkovnyak, P. Khalili Amiri, K. L Wang* “Switching of perpendicular magnetization by spin-orbit torques in the absence of external magnetic fields” Nature Nanotechnology 9, 548 (2014); Highlighted in Nature Nanotech. - News and Views; 引用次數：600次 [國際上首次證明了，在具有面內對稱性破缺的楔形結構中，電流產生的自旋軌道力矩可以在零磁場條件下驅動垂直磁矩翻轉]

(8) G. Q. Yu*, P. Upadhyaya, K. L. Wong, W. Jiang, J. G. Alzate, J. Tang, P. K. Amiri*, K. L. Wang* “Magnetization switching through spin-Hall-effect-induced chiral domain wall propagation” Physical Review B 89, 104421 (2014); 引用次數：100次 [揭示了自旋軌道矩驅動垂直磁矩翻轉是通過驅動手性磁疇壁的運動實現的。]

(9) Y. Liu, G. Q. Yu* “MRAM gets closer to the core” Nature Electronics 2,555 (2019) [受邀為英特爾研發團隊的最新研究進展撰寫評論文章。]

(10) G. Q. Yu* “Two-terminal MRAM with a spin” Nature Electronics 1, 496 (2018) [受邀為斯坦福研究團隊的最新研究進展撰寫評論文章。] ^[1] 

(1) Yao Guang#, Kejing Ran#, Junwei Zhang, Yizhou Liu, Senfu Zhang, Xuepeng Qiu, Yong Peng, Xixiang Zhang, Markus Weigand, Joachim Gräfe, Gisela Schütz, Gerrit van der Laan, Thorsten Hesjedal, Shilei Zhang*, Guoqiang Yu*, and Xiufeng Han “Superposition of Emergent Monopole and Antimonopole in CoTb Thin Films” Physical Review Letters 127, 217201 (2021) [發現CoTb合金薄膜中存在三維拓撲磁結構，實驗上直接證明了演生磁單極子和反單極子的疊加態磁結構。]

(2) Z. R. Yan, Y. Z. Liu, Y. Guang, K. Yue, J. F. Feng, R. K. Lake, G. Q. Yu*, and X. F. Han* “Skyrmion-Based Programmable Logic Device with Complete Boolean Logic Functions” Physical Review Applied 15, 064004 (2021)(Editors' Suggestion) [提出了通過操控局域交換偏置形成人工釘扎中心，構建出新型邏輯器件，實現了16種完整的布爾邏輯功能。]

(3) B. Cui, D. Yu, Z. Shao, Y. Liu, H. Wu, P. Nan, Z. Zhu, C. Wu, T. Guo, P. Chen, H. Zhou, L. Xi, W. Jiang, H. Wang, S. Liang, H. Du, K. L. Wang, W. Wang, K. Wu, X. Han, G. Zhang, H. Yang*, G. Q. Yu* “Néel-Type Elliptical Skyrmions in a Laterally Asymmetric Magnetic Multilayer” Advanced Materials 33, 2006924 (2021) [通過構建楔形薄膜，成功誘導出面內磁各向異性和DMI各向異性，進而實現室温橢圓形斯格明子。]

(4) Kejing Ran#, Yizhou Liu#, Yao Guang, David M Burn, Gerrit van der Laan, Thorsten Hesjedal*, Haifeng Du*, Guoqiang Yu*, Shilei Zhang* “Creation of a Chiral Bobber Lattice in Helimagnet-Multilayer Heterostructures” Physical Review Letters 126, 017204 (2021)；Editors' Suggestion；[通過構建多層膜/塊體材料異質結構，成功利用多層膜中的斯格明子在塊體材料中誘導實現磁浮子。]

(5) Y. Guang#, Y. Peng#, Z. Yan#, Y. Liu, J. Zhang, X. Zeng, S. Zhang, S. Zhang, D. M. Burn, N. Jaouen, J. Wei, H. Xu, J. Feng, C. Fang, G. v. d. Laan, T. Hesjedal, B. Cui, X. Zhang*, G. Q. Yu*, X. Han “Electron Beam Lithography of Magnetic Skyrmions” Advanced Materials 32, 2003003 (2020) [首次實驗證明了，可以通過電子束來影響反鐵磁異質結中交換偏置來產生單個斯格明子其及人工晶體。]

(6) Y. Guang#, I. Bykova#, Y. Liu#, G. Q. Yu*, E. Goering, M. Weigand, J. Gräfe, S. K. Kim, J. Zhang, H. Zhang, Z. Yan, W. Li, C. Wan, J. Feng, X. Wang, C. Guo, H. Wei, Y. Peng, Y. Tserkovnyak, X. Han, G. Schütz “Creating a 100-nm-scale zero-field skyrmion in exchange-biased multilayers through X-ray illumination” Nature Communications 11, 949 (2020) [首次實驗證明了，可以通過X射線技術來影響反鐵磁異質結中交換偏置來產生單個斯格明子其及人工晶體。]

(7) W. Li#, I. Bykova#, S. Zhang#, G. Q. Yu*, R. Tomasello, M. Carpentieri, Y. Liu, Y. Guang, J. Gräfe, M. Weigand, D. M. Burn, G. van der Laan, T. Hesjedal, Z. Yan, J. Feng, C. Wan, J. Wei, X. Wang, X. Zhang, H. Xu, C. Guo, H. Wei, G. Finocchio*, X. Han, G. Schütz “Anatomy of Skyrmionic Textures in Magnetic Multilayers” Advanced Materials 31, 1807683 (2019) [通過構建多層膜結構，實現了尺寸小於100 nm的室温斯格明子，並首次直接地證明了其具有三維的磁性結構。]

(8) G. Q. Yu#*, A. Jenkins#, X. Ma#, S. A. Razavi, C. He, G. Yin, Q.Shao, Q. He, H. Wu, W. Li, W. Jiang, X. Han, X. Li, A. C. B.Jayich, P. K. Amiri, K. L Wang* "Room-temperature skyrmions in an antiferromagnet-based heterostructure" Nano Letters 18, 980 (2018); [利用交換偏置有效磁場，在反鐵磁(IrMn)/鐵磁異質結中實現了室温不需要外加磁場的斯格明子穩定相。]

(9) X. Ma#*, G. Q. Yu#, S. A. Razavi, S. S. Sasaki, X. Li, K. Hao, S. H. Tolbert, K. L. Wang, and X. Li* "Dzyaloshinskii-Moriya interaction across an antiferromagnet-ferromagnet interface" Physical Review Letters 119, 027202 (2017) [實驗揭示了反鐵磁(IrMn)/鐵磁異質結中同樣存在相當大的DM相互作用，並揭示了DM相互作用與其反鐵磁序的相關性。]

(10) G. Q. Yu*, P. Upadhyaya, Q. Shao, H. Wu, G. Yin, X. Li, C. He, W. Jiang, X. Han, P. K. Amiri*, and K. L. Wang* "Room-temperature skyrmion shift device for memory application" Nano Letters 17 (1), pp 261–268 (2017); 引用次數：200次 [通過控制電流脈衝的幅值和持續時間，實現了原型器件中單個斯格明子的精準寫入和移動。基於此，首次實現了以斯格明子為信息載體的原型移位寄存器件。]

(11) G. Q. Yu#, P. Upadhyaya#, X. Li, W. Li, S. K. Kim, Y. Fan, K. L Wong, Y. Tserkovnyak, P. K. Amiri*, K. L Wang* “Room-temperature creation and spin-orbit torque manipulation of skyrmions in thin films with engineered asymmetry” Nano Letters 16, 1981 (2016) 引用次數：250次 [首次證明了通過調製薄膜材料中的磁各向異性能夠在室温、低磁場的條件下產生穩定的斯格明子相。] ^[1]