Nearly fully opened charge density wave gap in the quasi-two-dimensional conductor γ−Mo4O11 : A comparative study with η−Mo4O11

Abstract

The accommodation of Luttinger liquid behavior and unique quasiparticles in the charge density wave (CDW) state has led to renewed interest in the low-dimensional molybdenum bronzes. Here, the authors report a comprehensive experimental study on the quasi-two-dimensional CDW oxide bronzes Mo${}_{4}$O${}_{11}$, in which the CDW instability is dominated by hidden Fermi surface nesting, resulting in magnetic field induced quantum oscillations. Different from the monoclinic $\ensuremath{\eta}$ phase, the orthorhombic $\ensuremath{\gamma}$ phase shows a flexible CDW transition with a nearly fully opened gap, as seen in nonlinear transport behavior related to the CDW sliding motion, which is only observed in quasi-one-dimensional systems.