Seminar: Antiferromagnetic Spintronics

Abstract: Antiferromagnets with zero net magnetic moment, strong anti-interference and ultrafast switching speed have potential competitiveness in high-density information storage and high-frequency processing. Electrical switching of antiferromagnets is at the heart of their device application [1,2]. The antidamping torque-induced switching of Néel order is attained in a biaxial antiferromagnetic insulator NiO, which is manifested electrically via spin Hall magnetoresistance in NiO (100)/Pt bilayers [3]. The antiferromagnetic moments are switched towards the current direction, different from the vertical configuration in the fieldlike torque scenario (e.g., CuMnAs and Mn₂Au) [1,4]. We use ferroelastic strain from piezoelectric materials to switch the uniaxial magnetic anisotropy and the Néel order reversibly in antiferromagnetic Mn₂Au films with an electric field of only a few kV/cm at room temperature. Owing to the uniaxial magnetic anisotropy, a ratchet-like switching behavior driven by the Néel spin-orbit torque is observed in the Mn₂Au, which can be reversed by electric fields [5]. Electrical switching of antiferromagnetic moments pave the way for all-electrical writing and readout in antiferromagnetic spintronics, such as tunneling junctions [6,7].

Profile: Cheng SONG has completed his PhD at 2009 from Tsinghua University and postdoctoral studies from University of Regensburg. He was a Humboldt fellowship, and now is a tenured associate professor in Tsinghua Univerisy, working on magnetic films and spintronic devices. He has published more than 100 papers in reputed journals with citation >4000 according to Web of Science, H=35. His present research interest is antiferromagnet spintronics and electrical control of magnetism.