Tunneling investigation of charge density wave energy gap in IT-TaS2

The charge density wave induced energy gap has been observed by tunneling measurements over the nearly-commensurate phase of IT-TaS2. The energy gap stays near 0.5eV from 215K up to around 280K, and above this temperature it decreases with increasing the temperature. In addition to the structures giving the energy gap, a group of peak structures connected with the charge density waves have been observed in the dI/dV vs. V curves of the tunneling junctions, though the origin of those is not clarified yet. Connections of the energy gap with the electronic properties of this material are discussed.