Magnetism originates from the spin of the unpaired electrons and their interaction with the unquenched orbital momenta. Thanks to the development of quantum mechanics, the magnetic properties are deeply understood. It has been a cut-edge research field to manipulate the spin behavior of paramagnetic centers from chemical and physical approaches.

自旋电子学利用电子自旋进行信息的传递、处理与存储，比传统微电子学具有运算速度更快，能耗更低等优势，被认为是将来发展打破摩尔定律极限的关键信息技术之一。目前自旋电子学应用面临着三大挑战：自旋的产生和注入，自旋的长程输运，以及自旋的调控和探测。这些问题的解决一方面在于设计具有特定性质的自旋电子学材料，例如双极磁性半导体，铁磁半金属等，另一方面在于发展精准的器件构造和测量技术。

To understand the Nature, scientists have viewed the world from different angles and built various research frameworks according to the level of inquiry, e.g., macro and micro sciences for studying bulk substances and molecular species, respectively. A philosophical linkage here is the reductionism conjecture, assuming that the former (i.e., a bulk substance) is reducible to the latter (i.e., simpler molecules).