While conventional complementary metal-oxide semiconductors (CMOS), a technology used today in all types of electronics, rely on electrons' charge to power devices, the emerging field of spintronics exploits another aspect of electrons — their spin, which could be manipulated by electric and magnetic fields.
“With the use of nanoscaled magnetic materials, spintronics or electronic devices, when switched off, will not have a stand-by power dissipation problem. With this advantage, devices with much lower power consumption, known as non-volatile electronics, can become a reality,” said the study's corresponding author, Wang, whose team carried out the research. “Our approach provides a possible solution to address the critical challenges facing today's microelectronics industry and sheds light on the future of spintronics.”
“We've built a new class of material with magnetic properties in a dilute magnetic semiconductor (DMS) system,” said Xiu, a UCLA senior researcher and lead author of the study. “Traditionally, it's been really difficult to enhance the ferromagnetism of this material above room temperature. However in our work, by using a type of quantum structure, we've been able to push the ferromagnetism above room temperature.”
Ferromagnetism is the phenomenon by which certain materials form permanent magnets. In the past, the control of magnetic properties has been accomplished by applying an electric current. For example, passing an electric current will generate magnetic fields. Unfortunately, using electric currents poses significant challenges for reducing power consumption and for device miniaturization.
“You can think of a transformer, which passes a current to generate a magnetic field. This will have huge power dissipation (heat),” Xiu said. “In our study, we tried to modulate the magnetic properties of DMS without passing the current.”
Ferromagnetic coupling in DMS systems, the researchers say, could lead to a new breed of magneto-electronic devices that alleviate the problems related to electric currents. The electric field–controlled ferromagnetism reported in this study shows that without passing an electric current, electronic devices could be operated and functioning based on the collective spin behavior of the carriers. This holds great promise for building next-generation nanoscaled integrated chips with much lower power consumption.