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.
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 -