物理学报2025，Vol.74Issue(13)：398-403,6.DOI:10.7498/aps.74.20250346
轻金属Cr薄膜的逆轨道霍尔效应
Inverse orbital Hall effect in light metal Cr films
摘要
Abstract
Orbitronic devices have aroused considerable interest due to their unique advantage of being independent of strong spin-orbit coupling.Light metal chromium(Cr)with high orbital Hall conductivity has significant potential for application in orbit-spintronic devices.In this study,we present experimental verification of the inverse orbital Hall effect(IOHE)in Cr thin films and systematically investigate the underlying physical mechanisms of orbital-to-charge current conversion.The Cr/Ni and Pt/Ni heterostructures are fabricated on Al2O3 substrates via magnetron sputtering.Terahertz time-domain spectroscopy is employed to measure the terahertz emission signal.The Cr/Ni heterostructure exhibits the same positive terahertz polarity as the ISHE-dominant Pt/Ni heterostructure,despite the Cr layer owing negative spin Hall angle,which confirms the IOHE of Cr/Ni heterostructure.In the Cr/Ni heterostructures,femtosecond laser excitation generates spin current in the ferromagnetic Ni layer,which is converted into orbital current via its spin-orbit coupling.This orbital current propagates into the Cr layer where it is transformed into charge current through the IOHE.Furthermore,the increase of the Cr thickness(2-40 nm)weakens the terahertz emission of Cr/Ni heterostructures due to enhanced optical absorption of Cr layers reducing spin current generation in Ni layers.However,the optimization of Ni thickness(3-10 nm)significantly enhances the terahertz emission by improving the spin-to-orbital current conversion efficiency.This work provides experimental evidence for IOHE in Cr films and demonstrates the crucial role of ferromagnetic layer engineering in spin-to-orbital current conversion efficiency,providing innovative perspectives for designing and optimizing the performance of orbitronic devices.关键词
轻金属Cr薄膜/逆轨道霍尔效应/太赫兹Key words
light material Cr film/inverse orbital Hall effect/terahertz引用本文复制引用
陈锋,王平,张志佳,何康,冯正,张德林..轻金属Cr薄膜的逆轨道霍尔效应[J].物理学报,2025,74(13):398-403,6.基金项目
国家重点研发计划(批准号:2022YFA1204003)、国家自然科学基金(批准号:52271240,62027807)、沧州市重点研发计划(批准号:222104008)和河北省自然科学基金(批准号:E2023110012)资助的课题. Project supported by the National Key R&D Program of China(Grant No.2022YFA1204003),the National Natural Science Foundation of China(Grant Nos.52271240,62027807),the Key R&D Program of Cangzhou City,China(Grant No.222104008),and the Hebei Natural Science Foundation,China(Grant No.E2023110012). （批准号:2022YFA1204003）
