Unusual spectral behavior of charge-density waves with imperfect nesting in a quasi-one-dimensional metal.
Low-temperature electronic properties of the charge-density-wave system NbSe3 are reported from angle-resolved photoemission at 15 K. The effect of two instabilities q(1) and q(2) on the k-resolved spectral function is observed for the first time. With a pseudogap background, the gap spectra exhibit maxima at Delta*(1) approximately 110 meV and Delta*(2) approximately 45 meV. Imperfectly nested sections of the Fermi surface lack a Fermi-Dirac edge, and show the signature of a dispersion that is modified by self-energy effects. The energy scale is of the order of the effective gap 2 Delta*(2). The effect disappears above T2, suggesting a correlation with the charge-density-wave state.
Schäfer
J
J
Institut für Experimentalphysik, Universität Augsburg, 86135 Augsburg, Germany.
Sing
M
M
Claessen
R
R
Rotenberg
Eli
E
Zhou
X J
XJ
Thorne
R E
RE
Kevan
S D
SD