中国有色金属学会会刊(英文版)
中國有色金屬學會會刊(英文版)
중국유색금속학회회간(영문판)
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
2006年
z1期
146-153
,共8页
quantum point contact%magnetoresistance%quantum domain wall%electron wave-guide%oscillatory magnetoresistance
Recent work on magnetic quantum point contacts (QPCs) was discussed. Complete magnetoresistance loops across Co QPCs as small as a single atom was measured. The remarkable feature of these QPCs is the rapid oscillatory decay in magnetoresistance with the increase of contact size. In addition,stepwise or quantum magnetoresistance loops are observed,resulting from varying transmission probability of the available discrete conductance channels because the sample is cycled between the ferromagnetic (F) and antiferromagnetic (AF) aligned states. Quantized conductance combined with spin dependent transmission of electron waves gives rise to a multi-channel system with a quantum domain wall acting as a valve,i.e.,a quantum spin-valve. Behavior of a few-atom QPC is built on the behavior of a single-atom QPC and hence the summarization of results as 'single-atom spintronics'. An evolutionary trace of spin-dependent electron transmission from a single atom to bulk is provided,the requisite hallmarks of artefact-free magnetoresistance is established across a QPC - stepwise or quantum magnetoresistance loops and size dependent oscillatory magnetoresistance.