Spin ordering and electronic texture in the bilayer iridate Sr$_3$Ir$_2$O$_7$

TL;DR

This study investigates the complex magnetic and electronic phases in bilayer iridate Sr$_3$Ir$_2$O$_7$, revealing multiple phase transitions and coexistence of magnetic and electronic orders near the metal-insulator boundary.

Contribution

It provides new insights into the high-temperature magnetic phase, reorientation at 280 K, and electronic phase behavior below 70 K in Sr$_3$Ir$_2$O$_7$, highlighting the interplay of multiple order parameters.

Findings

High-temperature magnetic phase persists above 600 K.

Magnetic reorientation occurs at 280 K.

Electronic phase freezes below approximately 70 K.

Abstract

Through a neutron scattering, charge transport, and magnetization study, the correlated ground state in the bilayer iridium oxide Sr$_3$Ir$_2$O$_7$ is explored. Our combined results resolve scattering consistent with a high temperature magnetic phase that persists above 600 K, reorients at the previously defined $T_{AF}=280$ K, and coexists with an electronic ground state whose phase behavior suggests the formation of a fluctuating charge or orbital phase that freezes below $T^{*}\approx70$ K. Our study provides a window into the emergence of multiple electronic order parameters near the boundary of the metal to insulator phase transition of the 5d $J_{eff}=1/2$ Mott phase.