The spin-orbit Mott insulator Sr3Ir2O7 provides a fascinating playground to explore insulator-metal transition driven by intertwined charge, spin, and lattice degrees of freedom. Here, we report high pressure electric resistance and resonant inelastic x ray scattering measurements on single crystal Sr3Ir2O7 up to 63 65 GPa at 300 K. The material becomes a confined metal at 59.5 GPa, showing metallicity in the ab plane but an insulating behavior along the c axis. Such an unusual phenomenon resembles the strange metal phase in cuprate superconductors. Since there is no sign of the collapse of spin orbit or Coulomb interactions in x-ray measurements, this novel insulator metal transition is potentially driven by a first-order structural change at nearby pressures. Our discovery points to a new approach for synthesizing functional materials.
@article{arxiv.1605.07582,
title = {Pressure-Induced Confined Metal from the Mott Insulator Sr3Ir2O7},
author = {Yang Ding and Liuxiang Yang and Cheng-Chien Chen and Heung-Sik Kim and Myung Joon Han and Wei Luo and Zhenxing Feng and Mary Upton and Diego Casa and Jungho Kim and Thomas Gog and Zhidan Zeng and Gang Cao and Ho-kwang Mao and Michel van Veenendaal},
journal= {arXiv preprint arXiv:1605.07582},
year = {2016}
}