Observation of a gap in the far-infrared magneto-absorption of (TMTSF) 2ClO4 : possibility of one-dimensional fluctuating superconductivity

Abstract

A new method for determining the energy gap of superconductors is presented. The far-infrared magneto-absorption is measured by looking at the change of transmission through a grid of the material upon application of a magnetic field. Excellent agreement with tunnelling data is obtained for Pb and Nb wires. On needle-like (TMTSF)2ClO4 crystals, the application of a field of 0.2 tesla leads to an increase of the absorption below 3.8 meV. This gap is in agreement with the proposed model of One-Dimensional fluctuating superconductivity above the phase transition temperature.