Enhanced Electron Heat Conduction in TaS(3) 1D Metal Wire

The 1D wire TaS(3) exhibits metallic behavior at room temperature but changes into a semiconductor below the Peierls transition temperature (T(p)), near 210 K. Using the 3ω method, we measured the thermal conductivity [Formula: see text] of TaS(3) as a function of temperature. Electrons dominate the heat conduction of a metal. The Wiedemann–Franz law states that the thermal conductivity [Formula: see text] of a metal is proportional to the electrical conductivity σ with a proportional coefficient of L(0), known as the Lorenz number—that is, [Formula: see text]. Our characterization of the thermal conductivity of metallic TaS(3) reveals that, at a given temperature T, the thermal conductivity κ is much higher than the value estimated in the Wiedemann–Franz (W-F) law. The thermal conductivity of metallic TaS(3) was approximately 12 times larger than predicted by W-F law, implying [Formula: see text]. This result implies the possibility of an existing heat conduction path that the Sommerfeld theory cannot account for.