Max Planck POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 37673, Korea.
Department of Physics, Chung-Ang University, Seoul 06911, Korea.
Nat Commun. 2016 Sep 21;7:12912. doi: 10.1038/ncomms12912.
Molecular quantum magnetism involving an isolated spin state is of particular interest due to the characteristic quantum phenomena underlying spin qubits or molecular spintronics for quantum information devices, as demonstrated in magnetic metal-organic molecular systems, the so-called molecular magnets. Here we report the molecular quantum magnetism realized in an inorganic solid Ba3Yb2Zn5O11 with spin-orbit coupled pseudospin-½ Yb(3+) ions. The magnetization represents the magnetic quantum values of an isolated Yb4 tetrahedron with a total (pseudo)spin 0, 1 and 2. Inelastic neutron scattering results reveal that a large Dzyaloshinsky-Moriya interaction originating from strong spin-orbit coupling of Yb 4f is a key ingredient to explain magnetic excitations of the molecular magnet states. The Dzyaloshinsky-Moriya interaction allows a non-adiabatic quantum transition between avoided crossing energy levels, and also results in unexpected magnetic behaviours in conventional molecular magnets.
由于自旋量子比特或分子自旋电子学在量子信息器件中的特征量子现象，涉及孤立自旋态的分子量子磁性引起了特别的关注，这在磁性金属-有机分子体系中得到了证实，即所谓的分子磁体。在这里，我们报道了在具有自旋轨道耦合的赝自旋-½ Yb(3+)离子的无机固体 Ba3Yb2Zn5O11 中实现的分子量子磁性。磁化强度代表了具有总（赝）自旋 0、1 和 2 的孤立 Yb4 四面体的磁量子值。非弹性中子散射结果表明，源于 Yb 4f 强自旋轨道耦合的大 Dzyaloshinsky-Moriya 相互作用是解释分子磁体状态磁激发的关键因素。Dzyaloshinsky-Moriya 相互作用允许在避免交叉能级之间进行非绝热量子跃迁，并且也导致传统分子磁体中出现意想不到的磁性行为。
