Magnetic Field-Induced Insulator-Semimetal Transition in a Pyrochlore Nd2Ir2O7.
We investigate magnetotransport properties in a single crystal of pyrochore-type Nd2Ir2O7. The metallic conduction is observed on the antiferromagnetic domain walls of the all-in-all-out-type Ir 5d moment ordered insulating bulk state that can be finely controlled by an external magnetic field along [111]. On the other hand, an applied field along [001] induces the bulk phase transition from insulator to semimetal as a consequence of the field-induced modification of the Nd 4f and Ir 5d moment configurations. A theoretical calculation consistently describing the experimentally observed features suggests a variety of exotic topological states as functions of electron correlation and Ir 5d moment orders, which can be finely tuned by the choice of rare-earth ion and magnetic field, respectively.
Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan.
K
K
Ueda
Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan.
J
J
Fujioka
Center for Emergent Matter Science (CEMS), RIKEN Advanced Science Institute (ASI), Wako 351-0198, Japan.
B-J
BJ
Yang
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
J
J
Shiogai
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
A
A
Tsukazaki
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
S
S
Nakamura
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
S
S
Awaji
Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan.|Center for Emergent Matter Science (CEMS), RIKEN Advanced Science Institute (ASI), Wako 351-0198, Japan.
N
N
Nagaosa
Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan.|Center for Emergent Matter Science (CEMS), RIKEN Advanced Science Institute (ASI), Wako 351-0198, Japan.
Y
Y
Tokura