Chromium tellurium compounds are important two-dimensional van der Waals ferromagnetic materials with high Curie temperature and chemical stability in air,which is promising for applications in spintronic devices.Here...Chromium tellurium compounds are important two-dimensional van der Waals ferromagnetic materials with high Curie temperature and chemical stability in air,which is promising for applications in spintronic devices.Here,highquality spin-orbital-torque(SOT)device,Bi_(2)Te_(3)/CrTe_(2)heterostructure was epitaxially grown on Al_(2)O_(3)(0001)substrates.Anomalous Hall measurements indicate the existence of strong ferromagnetism in this device with the CrTe_(2)thickness down to 10 nm.In order to investigate its micromagnetic structure,cryogenic magnetic force microscope(MFM)was utilized to measure the magnetic domain evolutions at various temperatures and magnetic fields.The virgin domain state of the device shows a worm-like magnetic domain structure with the size around 0.6μm-0.8μm.Larger irregular-shape magnetic domains(>1μm)can be induced and pinned,after the field is increased to coercive field and ramped back to low fields.The temperature-dependent MFM signals exhibit a nice mean-field-like ferromagnetic transition with Curie temperature around 201.5 K,indicating a robust ferromagnetic ordering.Such a device can be potentially implemented in future magnetic memory technology.展开更多
新一代移动通信网络不断演进为高密集、无定型、立体分层的异构网络,移动性管理旨在保证用户设备(user equipment,UE)移动通信服务的连续性和无缝切换及降低信令开销等。移动性管理问题正成为异构小蜂窝网络(heterogeneous and small ce...新一代移动通信网络不断演进为高密集、无定型、立体分层的异构网络,移动性管理旨在保证用户设备(user equipment,UE)移动通信服务的连续性和无缝切换及降低信令开销等。移动性管理问题正成为异构小蜂窝网络(heterogeneous and small cell networks,Het Nets)中无线资源管理需要应对的关键性挑战之一。阐述了移动性管理的一般性问题,根据移动性管理的主要特征给出了一个综合分类:整体切换性能增强、小蜂窝发现与识别增强和无线链路失效(radio link failure,RLF)恢复增强。此外,依据此分类对近年来第三代合作伙伴计划(3rd generation partnership project,3GPP)成员在无线接入网(radio access network,RAN)标准化工作组历次会议中提出的主要移动性管理增强方案进行了分类阐述和性能对比。对异构小蜂窝网络的移动性管理所面临的挑战和未来研究的趋势进行展望,并在此基础上进行了总结。展开更多
基金Project supported by the National Key Research and Development Program of China (Grant No.2022YFA1403000)the National Natural Science Foundation of China (Grant No.12374161)+3 种基金the Fund from the Science and Technology Commission of Shanghai Municipality (Grant No.21PJ410800)the support from the National Natural Science Foundation of China (Grant No.92164104)the Rising Star Program of Shanghai (Grant No.21QA1406000)the Open Fund of State Key Laboratory of Infrared Physics。
文摘Chromium tellurium compounds are important two-dimensional van der Waals ferromagnetic materials with high Curie temperature and chemical stability in air,which is promising for applications in spintronic devices.Here,highquality spin-orbital-torque(SOT)device,Bi_(2)Te_(3)/CrTe_(2)heterostructure was epitaxially grown on Al_(2)O_(3)(0001)substrates.Anomalous Hall measurements indicate the existence of strong ferromagnetism in this device with the CrTe_(2)thickness down to 10 nm.In order to investigate its micromagnetic structure,cryogenic magnetic force microscope(MFM)was utilized to measure the magnetic domain evolutions at various temperatures and magnetic fields.The virgin domain state of the device shows a worm-like magnetic domain structure with the size around 0.6μm-0.8μm.Larger irregular-shape magnetic domains(>1μm)can be induced and pinned,after the field is increased to coercive field and ramped back to low fields.The temperature-dependent MFM signals exhibit a nice mean-field-like ferromagnetic transition with Curie temperature around 201.5 K,indicating a robust ferromagnetic ordering.Such a device can be potentially implemented in future magnetic memory technology.
基金supported by the National Key R&D Program of China(2017YFA0305400 and 2019YFA0704900)Chinese Academy of Sciences-Shanghai Science Research Center(CAS-SSRC-YH2015-01)+9 种基金Double First-Class Initiative Fund of Shanghai Tech Universitythe support from the Engineering and Physical Sciences Research Council Platform Grant(EP/M020517/1)the Major Research Plan of the National Natural Science Foundation of China(NSFC,92065201)Shanghai Municipal Science and Technology Major Project(2018SHZDZX02)the support from the NSFC(52088101 and 11974394)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB33000000)the support from Shanghai Committee of Science and Technology(22ZR1441800)Shanghai-XFEL Beamline Project(SBP)(31011505505885920161A2101001)the support from the NSFC(12004248)and the support from the NSFC(12104304)Shanghai Sailing Program(20YF1430500)。
文摘新一代移动通信网络不断演进为高密集、无定型、立体分层的异构网络,移动性管理旨在保证用户设备(user equipment,UE)移动通信服务的连续性和无缝切换及降低信令开销等。移动性管理问题正成为异构小蜂窝网络(heterogeneous and small cell networks,Het Nets)中无线资源管理需要应对的关键性挑战之一。阐述了移动性管理的一般性问题,根据移动性管理的主要特征给出了一个综合分类:整体切换性能增强、小蜂窝发现与识别增强和无线链路失效(radio link failure,RLF)恢复增强。此外,依据此分类对近年来第三代合作伙伴计划(3rd generation partnership project,3GPP)成员在无线接入网(radio access network,RAN)标准化工作组历次会议中提出的主要移动性管理增强方案进行了分类阐述和性能对比。对异构小蜂窝网络的移动性管理所面临的挑战和未来研究的趋势进行展望,并在此基础上进行了总结。
