Giant magnetoresistance through a single molecule
Giant magnetoresistance through a single molecule
复制标题
DOI：
10.1038/nnano.2011.11
复制
发表时间：
2011-03-01
影响因子：
38.3
通讯作者：
Wulfhekel, Wulf
中科院分区：
文献类型：
--
作者：
Schmaus, Stefan;Bagrets, Alexei;Wulfhekel, Wulf
磁阻是由施加的磁场引起的材料系统的电阻变化。巨磁阻发生在包含由金属非磁性垫片分隔的铁磁接触的结构中，并且现在是硬盘驱动器和新型随机存取存储器的读取头的基础。使用绝缘体（例如，分子薄膜）而不是金属作为间隔物会产生隧道磁阻，对于给定的磁场强度，隧道磁阻通常会产生较大的电阻变化，但也会产生较高的电阻，这对于实际器件操作来说是一个缺点。在这里，我们展示了扫描隧道显微镜铁磁尖端接触的单个非磁性氢酞菁分子的巨磁阻。我们测得磁阻为 60%，电导为 0.26G(o)，其中 G(o) 是电导量子。理论分析认为分子和电极轨道的自旋相关杂化是大磁阻的原因。
Magnetoresistance is a change in the resistance of a material system caused by an applied magnetic field. Giant magnetoresistance occurs in structures containing ferromagnetic contacts separated by a metallic non-magnetic spacer, and is now the basis of read heads for hard drives and for new forms of random access memory. Using an insulator (for example, a molecular thin film) rather than a metal as the spacer gives rise to tunnelling magnetoresistance, which typically produces a larger change in resistance for a given magnetic field strength, but also yields higher resistances, which are a disadvantage for real device operation. Here, we demonstrate giant magnetoresistance across a single, nonmagnetic hydrogen phthalocyanine molecule contacted by the ferromagnetic tip of a scanning tunnelling microscope. We measure the magnetoresistance to be 60% and the conductance to be 0.26G(o), where G(o) is the quantum of conductance. Theoretical analysis identifies spin-dependent hybridization of molecular and electrode orbitals as the cause of the large magnetoresistance.