Impurity-induced transition to a Mott insulator in Sr$_3$Ru$_2$O$_7$

R. Mathieu; A. Asamitsu; Y. Kaneko; J. P. He; X. Z. Yu; R. Kumai; Y. Onose; N. Takeshita; T. Arima; H. Takagi; Y. Tokura

doi:10.1103/PhysRevB.72.092404

paper

Impurity-induced transition to a Mott insulator in Sr $_{3}$ Ru $_{2}$ O $_{7}$

arXiv:cond-mat/0509227 · doi:10.1103/PhysRevB.72.092404

Abstract

The electrical, magnetic, and structural properties of Sr $_{3}$ (Ru $_{1 - x}$ Mn $_{x}$ ) $_{2}$ O $_{7}$ (0 $\leq x \leq$ 0.2) are investigated. The parent compound Sr $_{3}$ Ru $_{2}$ O $_{7}$ is a paramagnetic metal, critically close to magnetic order. We have found that, with a Ru-site doping by only a few percent of Mn, the ground state is switched from a paramagnetic metal to an antiferromagnetic insulator. Optical conductivity measurements show the opening of a gap as large as 0.1 eV, indicating that the metal-to-insulator transition is driven by the electron correlation. The complex low-temperature antiferromagnetic spin arrangement, reminiscent of those observed in some nickelates and manganites, suggests a long range orbital order.

REVTeX 4 style; 5 pages, 4 figures

Impurity-induced transition to a Mott insulator in Sr3​Ru2​O7​

Abstract

Impurity-induced transition to a Mott insulator in Sr $_{3}$ Ru $_{2}$ O $_{7}$