Semiconductors made progress in magnetic semiconductor (Ga,Mn)As research

Zhao Jianhua, member of the State Key Laboratory of Semiconductor Superlattices, Institute of Semiconductors, Chinese Academy of Sciences, and colleagues Xiong Peng, professor at Florida State University, have made new advances in magnetic tuning of magnetic semiconductor (Ga, Mn) As films in organic self-assembled monolayers. The relevant results were published in Advanced Materials (2015, 27, 8043–8050, DOI: 10.1002/adma.201503547) and were selected as the first edition of the journal (DOI: 10.1002/adma.201570332).

In recent years, the intersection of molecular interface chemistry and spintronics has received a lot of attention. The use of molecular interfaces to control the layout of electron spins in magnetic materials can drive the spin orientation of carrier sets, or coherent manipulation of individual electrons and a few electron spins. Wang Xiaolei et al. studied the modulation of (Cu,Mn)As on Curie temperature, coercivity, spin transport, and Hall effect at the interface between organic molecules and (Ga,Mn)As films. Holes introduced by Mn doping lead to ferromagnetic exchange between local Mn ions in (Ga,Mn)As, and the magnetic properties of (Ga,Mn)As are usually regulated by an external electric field to adjust the carrier concentration. However, this method has a very limited range of Curie temperature control and can usually only reach several K. Wang Xiaolei et al. used a nano-pointing instrument (DPN), a new technology for lithography and nanolithography based on atomic force microscopy, to achieve self-assembled organic molecular patterns ranging from 70 nanometers to 10 micrometers. Different organic molecules are attached to the (Ga,Mn)As surface by thermal evaporation and chemical adsorption, respectively, to provide hole and electron injection, and induce large carrier concentration changes in (Ga,Mn)As films. Enhancing and weakening the magnetic properties of the semiconductor film, the Curie temperature changes up to 36 K, which is much higher than that achieved by external electric field regulation. This work provides a new means of regulating the spin in magnetic semiconductors, which is of great significance both for basic research and for future information storage and quantum computing.

This work has received financial support from the National Natural Science Foundation of China, the Ministry of Science and Technology, and the Chinese Academy of Sciences.

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