Peierls transition in two-dimensional metallic monophosphate tungsten bronzes

Abstract

Abstract The two-dimensional metallic bronzes made of ReO3-type layers of MoO6 or WO6 octahedra present quasi-one-dimensional (1D) electronic structures along three directions of preferential overlap of the t2g transition metal orbitals. They exhibit a Peierls instability towards the formation of charge density waves (CDW) at the 2kF critical wave vector allowing to nest simultaneously the Fermi surfaces associated to two quasi-1D band structures out of three. The Peierls transition is achieved through a periodic lattice distortion (PLD), that we analyse, in the present work, for the monophosphate tungsten bronzes. The Peierls critical temperature decreases in presence of disorder, which breaks the electron–hole pairs forming the CDW condensate, and in presence of misfit between the PLD wave vector and the 2kF nesting wave vector. The pair breaking effect accounts for the drop of the Peierls transition in the NaxP4W12O44 (x