Upper critical field of quasi one-dimensional superconductor (DMET-TSeF)2AuI2 under oriented magnetic fields

The superconductivity of quasi one-dimensional salt (DMET-TSeF)2AuI2 was studied in the oriented magnetic fields through the resistive measurement. The upper critical fields Hc2 in the magnetic fields parallel to the highest and intermediate conductive a- and c-axes tend to exceed the Pauli paramagnetic limit. However, it is difficult to determine these values because the behaviour below 0.3 K is obscured by an electronic phase transition. The coherence lengths are evaluated from the slopes of Hc2(T) curves near Tc as ξa(0)≈100 nm, ξb(0)≈2 nm, ξc(0)≈30 nm.