TY - JOUR
T1 - Quadratic Fermi node in a 3D strongly correlated semimetal
AU - Kondo, Takeshi
AU - Nakayama, M.
AU - Chen, R.
AU - Ishikawa, J. J.
AU - Moon, E. G.
AU - Yamamoto, T.
AU - Ota, Y.
AU - Malaeb, W.
AU - Kanai, H.
AU - Nakashima, Y.
AU - Ishida, Y.
AU - Yoshida, R.
AU - Yamamoto, H.
AU - Matsunami, M.
AU - Kimura, S.
AU - Inami, N.
AU - Ono, K.
AU - Kumigashira, H.
AU - Nakatsuji, S.
AU - Balents, L.
AU - Shin, S.
N1 - Funding Information:
This work was supported by JSPS KAKENHI (Nos 24740218, 25220707 and 25707030), by the Photon and Quantum Basic Research Coordinated Development Program from MEXT, by PRESTO, Japan Science and Technology Agency, Grants-in-Aid for Scientific Research (No. 25707030), by Grants-in-Aids for Scientific Research on Innovative Areas (15H05882 and15H05883), and Program for Advancing Strategic International Networks to Accelerate the Circulation of Talented Researchers (No. R2604) from the Japanese Society for the Promotion of Science. L.B. and R.C. were supported by DOE grant DE-FG02-08ER46524, and E.-G.M. was supported by the MRSEC Program of the NSF under Award No. DMR 1121053. We thank D. Hamane for technical assistance in the SEM measurement. The use of the facilities (the Materials Design and Characterization Laboratory and the Electronic Microscope Section) at the Institute for Solid State Physics, The University of Tokyo, is gratefully acknowledged.
PY - 2015/12/7
Y1 - 2015/12/7
N2 - Strong spin-orbit coupling fosters exotic electronic states such as topological insulators and superconductors, but the combination of strong spin-orbit and strong electron-electron interactions is just beginning to be understood. Central to this emerging area are the 5d transition metal iridium oxides. Here, in the pyrochlore iridate Pr 2 Ir 2 O 7, we identify a non-trivial state with a single-point Fermi node protected by cubic and time-reversal symmetries, using a combination of angle-resolved photoemission spectroscopy and first-principles calculations. Owing to its quadratic dispersion, the unique coincidence of four degenerate states at the Fermi energy, and strong Coulomb interactions, non-Fermi liquid behaviour is predicted, for which we observe some evidence. Our discovery implies that Pr 2 Ir 2 O 7 is a parent state that can be manipulated to produce other strongly correlated topological phases, such as topological Mott insulator, Weyl semimetal, and quantum spin and anomalous Hall states.
AB - Strong spin-orbit coupling fosters exotic electronic states such as topological insulators and superconductors, but the combination of strong spin-orbit and strong electron-electron interactions is just beginning to be understood. Central to this emerging area are the 5d transition metal iridium oxides. Here, in the pyrochlore iridate Pr 2 Ir 2 O 7, we identify a non-trivial state with a single-point Fermi node protected by cubic and time-reversal symmetries, using a combination of angle-resolved photoemission spectroscopy and first-principles calculations. Owing to its quadratic dispersion, the unique coincidence of four degenerate states at the Fermi energy, and strong Coulomb interactions, non-Fermi liquid behaviour is predicted, for which we observe some evidence. Our discovery implies that Pr 2 Ir 2 O 7 is a parent state that can be manipulated to produce other strongly correlated topological phases, such as topological Mott insulator, Weyl semimetal, and quantum spin and anomalous Hall states.
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U2 - 10.1038/ncomms10042
DO - 10.1038/ncomms10042
M3 - Article
AN - SCOPUS:84949525594
VL - 6
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
M1 - 10042
ER -