Low-temperature specific heat ofNbSe3: A reassessment

The analysis of low-temperature specific-heat measurements of ${\mathrm{NbSe}}_3$ between 0.1 and 7 K reveals three contributions: a phonon term with a ${\mathit{T}}^{2.93}$ law, a linear term 4T (erg ${\mathrm{g}}^{\mathrm{-}1}$ ${\mathrm{K}}^{\mathrm{-}1}$) due to free carriers, and an extra contribution following a ${\mathit{T}}^{0.74}$ law. Aging effects in the energy relaxation and the presence of low-energy excitations indicate that ${\mathrm{NbSe}}_3$, similar to other quasi-one-dimensional conductors, has a disordered ground state in its low-temperature Peierls state.