Direct observation of temperature-dependent Fermi surface nesting vectors in a quasi-one-dimensional conductor

We present the first direct observation of temperature-dependent Fermi wave vectors in the quasi-one-dimensional conductor K 0.3 MoO 3 . By monitoring the position of these vectors through the Peierls transition using angle-resolved photoemission spectroscopy, we demonstrate that the temperature dependence of the charge-density-wave vector observed in earlier experiments is actually that of the Fermi wave vectors.