title: Unusual spectral behavior of charge-density waves with imperfect nesting in a quasi-one-dimensional metal.
abstract: 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.
authors.affiliation: Institut für Experimentalphysik, Universität Augsburg, 86135 Augsburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schäfer
authors.forename: M
authors.initials: M
authors.lastname: Sing
authors.forename: R
authors.initials: R
authors.lastname: Claessen
authors.forename: Eli
authors.initials: E
authors.lastname: Rotenberg
authors.forename: X J
authors.initials: XJ
authors.lastname: Zhou
authors.forename: R E
authors.initials: RE
authors.lastname: Thorne
authors.forename: S D
authors.initials: SD
authors.lastname: Kevan