Colossal Magnetoresistance in a Mott Insulator via Magnetic Field-Driven Insulator-Metal Transition.
We present a new type of colossal magnetoresistance (CMR) arising from an anomalous collapse of the Mott insulating state via a modest magnetic field in a bilayer ruthenate, Ti-doped Ca_{3}Ru_{2}O_{7}. Such an insulator-metal transition is accompanied by changes in both lattice and magnetic structures. Our findings have important implications because a magnetic field usually stabilizes the insulating ground state in a Mott-Hubbard system, thus calling for a deeper theoretical study to reexamine the magnetic field tuning of Mott systems with magnetic and electronic instabilities and spin-lattice-charge coupling. This study further provides a model approach to search for CMR systems other than manganites, such as Mott insulators in the vicinity of the boundary between competing phases.
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
M
M
Zhu
Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA.
J
J
Peng
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
T
T
Zou
Helmholtz Zentrum Berlin, D-14109 Berlin, Germany.
K
K
Prokes
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
S D
SD
Mahanti
Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
T
T
Hong
Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA.
Z Q
ZQ
Mao
Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
G Q
GQ
Liu
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
X
X
Ke