High-resolution angle-resolved photoemission spectroscopy (ARPES) on the quasi-one-dimensional Peierls system ${\mathrm{K}}_{0.3}{\mathrm{MoO}}_3$ reveals a “hidden” open Fermi surface and band features displaying the symmetry properties of the underlying lattice. However, the ARPES line shapes and optical data suggest that the corresponding quasiparticles are heavily renormalized by strong electron-phonon interactions. The temperature dependence of the leading edge of the mostly incoherent spectrum bears signatures of the Peierls transition at $T_P=180\mathrm{}\hspace{0.5em}\mathrm{K}$ and of pretransitional fluctuations.

• Received 9 April 2002

DOI:https://doi.org/10.1103/PhysRevB.66.075107