Complete d-band dispersion relation in sodium cobaltates.
We utilize fine-tuned polarization selection coupled with excitation-energy variation of photoelectron signal to image the complete d-band dispersion relation in sodium cobaltates. A hybridization gap anticrossing is observed along the Brillouin zone corner and the full quasiparticle band is found to emerge as a many-body entity lacking a pure orbital polarization. At low dopings, the quasiparticle bandwidth (Fermion scale, many-body E(F) approximately 0.25 eV) is found to be smaller than most known oxide metals. The low-lying density of states is found to be in agreement with bulk-sensitive thermodynamic measurements for nonmagnetic dopings where the 2D Luttinger theorem is also observed to be satisfied.
Qian
D
D
Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08544, USA.
Wray
L
L
Hsieh
D
D
Viciu
L
L
Cava
R J
RJ
Luo
J L
JL
Wu
D
D
Wang
N L
NL
Hasan
M Z
MZ