Inhomogeneous superconductivity in organic conductors: the role of disorder and magnetic field

Abstract

Several experimental studies have shown the presence of spatially inhomogeneous phase coexistence of superconducting and non superconducting domains in low dimensional organic superconductors. The superconducting properties of these systems are found to be strongly dependent on the amount of disorder introduced in the sample regardless of its origin. The suppression of the superconducting transition temperature Tc shows clear discrepancy with the result expected from the Abrikosov-Gor'kov law giving the behavior of Tc with impurities. Based on the time dependent Ginzburg-Landau theory, we derive a model to account for the striking feature of Tc in organic superconductors for different types of disorder by considering the segregated texture of the system. We show that the calculated Tc quantitatively agrees with experiments. We also focus on the role of superconducting fluctuations on the upper critical fields Hc2 of layered superconductors showing slab structure where superconducting domains are sandwiched by non-superconducting regions. We found that Hc2 may be strongly enhanced by such fluctuations.

Charge-ordering transition in (TMTTF)2X explored via dilatometry

“…27 ). Such measurements could also reveal whether there exist similarities between the AO and the glass-like transition observed in fully deuterated/hydrogenated salts of κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br 82 , and how an inhomogeneous texture of the low temperature phases of these organic salts could explain the strong sensitivity of their superconducting properties to cooling effects 113 . In order to gain more insights into the screening and polarization effects in the (TMTCF) 2 X salts, systematic calculations of the Madelung energy 114 above and below the CO transition temperature, including the polarization effects induced by the anion shift, are required.…”

Spin density wave and superconducting properties of nanoparticle organic conductor assemblies

“…5a); b) as an assembly of weakly interacting nanoparticles (Fig. 5b) where the field easily penetrates, and the diamagnetic shielding arises from the sum of individual superconducting nanoparticles 23 .…”

Structural Aspects of the Bechgaard and Fabre Salts: An Update

“…In presence of such a texture superconductivity is achieved through Josephson coupling between AO superconducting domains through the non ordered regions. The quantitative evolution of T S has been calculated [169] using the dependence of L and l with the cooling rate. It is found that the rate of decrease of T S saturates in agreement with the experimental finding.…”