Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Rev Lett. 2013 Feb 8;110(6):066403. doi: 10.1103/PhysRevLett.110.066403. Epub 2013 Feb 6.
The electronic properties of Mott insulators realized in (111) bilayers of perovskite transition-metal oxides are studied. The low-energy effective Hamiltonians for such Mott insulators are derived in the presence of a strong spin-orbit coupling. These models are characterized by the antiferromagnetic Heisenberg interaction and the anisotropic interaction whose form depends on the d orbital occupancy. From exact diagonalization analyses on finite clusters, the ground state phase diagrams are derived, including a Kitaev spin liquid phase in a narrow parameter regime for t(2g) systems. Slave-boson mean-field analyses indicate the possibility of novel superconducting states induced by carrier doping into the Mott-insulating parent systems, suggesting the present model systems as unique playgrounds for studying correlation-induced novel phenomena. Possible experimental realizations are also discussed.
本文研究了（111）层钙钛矿过渡金属氧化物双层结构中实现的莫特绝缘体的电子性质。在存在强自旋轨道耦合的情况下，导出了这些莫特绝缘体的低能有效哈密顿量。这些模型的特点是反铁磁海森堡相互作用和各向异性相互作用，其形式取决于 d 轨道占据数。通过对有限团簇的精确对角化分析，得出了包括在 t(2g)体系的窄参数范围内存在 Kitaev 自旋液体相的基态相图。从奴玻色子平均场分析来看，在莫特绝缘母体系统中通过载流子掺杂诱导新型超导态的可能性表明，目前的模型系统是研究相关诱导新型现象的独特场所。还讨论了可能的实验实现。
