Spintronics with compensated ferrimagnets

Abstract

Magnetic information storage has been achieved by controlling and sensing the magnetic moment orientation of nanoscale ferromagnets. Recently, there has been concentrated effort to utilize materials with antiferromagnetic coupling as a storage medium to realize devices that switch faster, are more secure against external magnetic fields, and have higher storage density. Within this class of materials are ferrimagnets, whose magnetization can be reduced to zero by tuning parameters such as the chemical composition, temperature, and strain. Compared to conventional antiferromagnets, compensated ferrimagnets not only possess the aforementioned speed and density advantages but also allow the use of convenient electrical reading and writing mechanisms due to the existence of inequivalent magnetic sublattices. Recent research has demonstrated fast spin-torque switching, as well as efficient electrical reading with compensated ferrimagnets. Further material and device research using these zero-moment magnets promises a spintronic platform for fast and energy efficient information storage technology.