Corrections to the 1D Density of States -- Observation of a Coulomb Gap?.

We report the first systematic study of the corrections to the electron density of states of a 1D system, ultra-narrow granular aluminum wires. These corrections do not have the V(-1/2) dependence predicted by theory, but are significantly larger than the corrections observed in corresponding bulk samples. At high magnetic fields, low temperatures, and very low voltages, we see evidence of a logarithmic gap in the density of states.