原子尺度下的自旋操纵及其相应的自旋输运过程是目前自旋电子学研究的热点，也是高性能磁性存储器的理论基础。基于第一性原理计算方法，我们研究纳米团簇的电子结构和磁学性质，并进一步提出利用交换相互作用来固定具有反铁磁性质的纳米团簇的自旋方向。通过自旋极化的STM针尖和纳米团簇的相互作用，可以操纵团簇的自旋方向，实现数据的写入过程。用非平衡格林函数计算相应体系的输运系数和磁电阻，分析磁电阻的起因，研究磁各向异性能和外加偏置电压对体系的磁电阻的影响，实现对数据的读出过程。我们理论计算的结果完全可以在现有的实验条件下得以实现，为实验研究指明具体方向。

Spin manipulation and spin polarized transmission at the atomic scale is a very hot topic for spinctronics, and it is also the foundation for modern high-efficientcy data storage devices.We perofrm ab inito calculations to investigate the electronic and magnetic properties of nano custers. Based on these results, we propose that the spin direction of antiferromagnetic nano clusters can be fixed by the exchange interaction between atoms of the clusters. And the spin direction of atoms can be manipulated with spin polarzied STM tips, which can be used for data storage.By means of the non-equilibrium Green function method, we calculate the transmission coefficient and the magnetoresistance between STM tips and nano clusters.The interplay between the magnetic anisotropy energy and the magnetoresistance, and the bias dependent transmission are also been carefully studied.The effect predicted here can be proved experimentally with current technology.