The quantum effect of triple-perovskite antiferromagnets with triangular-lattice A3MB2O9 (A = Ba, Ca, and Sr; M = Co, Ni, and Mn; B = Sb, Nb)

Abstract As a typical two-dimensional frustrated quantum magnet, the triangular-lattice antiferromagnet demonstrates a series of exotic states from the complicated interplays of lattice, spin, electron, and orbit with the quantum and thermal fluctuation. From the ground state of a triangular-lattice Heisenberg antiferromagnet with coplanar 120° ordering, a series of the magnetization anomalies could manifest themselves under a magnetic field, such as the 1/3 magnetization plateau (Ms/3) and the umbrella-shaped phase. This Ms/3 plateau state is recognized as an up-up-down structure stabilized by the quantum effect. By surveying through an avalanche of theoretical research and experimental measurements to study the triangular-lattice antiferromagnet, this review article describes the current understanding of the magnetic properties of triple-perovskite antiferromagnets A 3 MB 2 O 9 (A = Ba, Ca, and Sr; M = Co, Ni, and Mn; B = Sb, Nb). With both bulk properties and spin dynamics, the fascinating insights into the quantum effect on the triangular lattice are discussed.