Pressure-Induced Confined Metal from the Mott Insulator Sr_{3}Ir_{2}O_{7}.
The spin-orbit Mott insulator Sr_{3}Ir_{2}O_{7} 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 Sr_{3}Ir_{2}O_{7} 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.
Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, China.|Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.|HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.
Yang
Y
Ding
Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, China.|HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.
Liuxiang
L
Yang
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.|Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
Cheng-Chien
CC
Chen
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
Heung-Sik
HS
Kim
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
Myung Joon
MJ
Han
Condensed Matter Theory Group, Department of Physics, Box 530, SE-751 21 Uppsala, Sweden.
Wei
W
Luo
Chemical Sciences and Engineering, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Zhenxing
Z
Feng
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Mary
M
Upton
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Diego
D
Casa
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Jungho
J
Kim
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Thomas
T
Gog
Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, China.|HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.
Zhidan
Z
Zeng
Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA.
Gang
G
Cao
Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, China.|HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.|Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C. 20015, USA.
Ho-Kwang
HK
Mao
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.|Department of Physics, Northern Illinois University, De Kalb, Illinois 60115, USA.
Michel
M
van Veenendaal