Antiferromagnetic spintronics

Within the field of spintronics, spin emission is a vital effect. Despite their zero net magnetisation, antiferromagnets and compensated ferrimagnets offer several advantages as spin emitters compared to ferromagnets. First, the spin dynamics reach the THz range and naturally lead to the possibility of generating faster spin current pulses. This has important applications in THz technologies and ultra-fast memories. Second, the zero net magnetisation results in negligible stray magnetic fields, thus reducing interference between nearby magnetic components. Finally, antiferromagnetic materials are much more abundant than ferromagnets, particularly in the family of dielectrics, offering more choice of materials to meet specific requirements such as ordering temperature, conductivity and fundamental symmetry constraints. Here, we study how quickly and how efficiently we can extract spin from a magnetically compensated material by using experimental techniques that range from transport measurements (spin-Seebeck and spin-Hall magnetoresistance) to fast spectroscopy (THz emission spectroscopy).