Mere giant magnetoresistance, which debuted in commercial hard drives back in 1998, represented the first example of so-called spintronics, or electronics based not on charge but spin, the property of an electron that makes it act like a tiny bar magnet.

• 不过仅有在1998年的商业化硬盘上首度亮相的巨磁电阻效应才是称之为自旋电子--或非基于电荷而是旋转（电子的这个特性使它像一个小型的条形磁铁）的电子----的首个例子。