Engineering a Spin-Orbital Magnetic Insulator by Tailoring Superlattices



J. Matsuno, K. Ihara, S. Yamamura, H. Wadati, K. Ishii, V. V. Shankar, Hae-Young Kee, H. Takagi



In  5 d  Ir oxides with an interplay of spin-orbit coupling and electron correlations, we have tailored a spin-orbital magnetic insulator out of a semimetal  SrIrO 3  by tuning the structure through superlattices [ ( SrIrO 3 ) m SrTiO 3 ] ( m = 1 , 2 , 3 , 4 , and  ). We observed the systematic decrease of the magnetic ordering temperature and the resistivity as a function of  m . The transition from the semimetal to the insulator is found to be closely linked to the appearance of magnetism at  m 3 . Long range magnetic ordering was realized even in the  m = 1  single layer superlattice, implying that the design and realization of novel electronic phases is feasible at the level of a single atomic layer in complex Ir oxides.