Emergent electronic and magnetic state in Ca$_{3}$Ru$_{2}$O$_{7}$ induced by Ti doping

We report an emergent electronic and magnetic state in the bilayer ruthenate Ca$_{3}$Ru$_{2}$O$_{7}$ upon doping with a small concentration of Ti on the Ru sites. In contrast to a quasi-two-dimensional metallic state in Ca$_{3}$Ru$_{2}$O$_{7}$, which has an antiferromagnetic state formed by ferromagnetic bilayers stacked antiferromagnetically along the c-axis [1,2], we find an insulating state with a ``G''-type nearest neighbor antiferromagnetic order in Ca$_{3}$(Ru$_{1-x}$Ti$_{x})_{2}$O$_{7}$ for $x$ $>$= 0.03 [3]. The close proximity of these two distinct electronic and magnetic states demonstrates unique competing magnetic interactions in Ca$_{3}$Ru$_{2}$O$_{7}$, which provides a rare opportunity to investigate the interplay between correlated metal physics and Mott physics. Work supported by U.S. DOE. \\[4pt] [1] W. Bao \textit{et al}., Phys. Rev. Lett. \textbf{100}, 247203 (2008).\\[0pt] [2] X. Ke \textit{et al}., Phys. Rev. B \textbf{84}, 014422 (2011).\\[0pt] [3] X. Ke \textit{et al}., Phys. Rev. B \textbf{84}, 201102 (R) (2011).