Organic Conductors and Superconducting Materials

The field of organic conductors and superconducting materials has evolved around π-conjugated molecules arranged into low-dimensional stacks or layers, where strong electron correlations, lattice vibrations and subtle structural features give rise to metallic, insulating and superconducting states. Charge-transfer salts derived from donors such as tetrathiafulvalene (TTF) or bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and acceptors like tetracyanoquinodimethane (TCNQ) form one- or two-dimensional lattices that underpin rich phase diagrams encompassing Mott metal–insulator transitions, charge ordering, spin liquids and unconventional superconductivity. The prototypical Bechgaard (TMTSF) and Fabre (TMTTF) salts revealed superconductivity under pressure, while the κ-type BEDT-TTF salts exhibit critical temperatures up to 14 K. In these systems, superconductivity frequently emerges adjacent to antiferromagnetic or charge-ordered phases, pointing to pairing mediated by spin or charge fluctuations rather than conventional phonons. The chemical tunability of molecular orbitals, intermolecular interactions and lattice degrees of freedom affords design pathways for flexible electronics, quantum sensors and lightweight superconducting wires. Advances in high-pressure techniques, ultrafast spectroscopy and theoretical modelling continue to deepen our understanding of correlation-driven phenomena and guide the synthesis of novel organic quantum materials.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Organic Conductors and Superconducting Materials publication trend

The graph below shows the total number of articles in organic conductors and superconducting materials across all publications each year (not limited to Nature Index journals).

Technical terms

Charge-transfer salt: A compound in which π-conjugated donor molecules transfer electrons to acceptor molecules, forming conducting stacks.

Mott insulator: A material predicted to be metallic by band theory but rendered insulating by strong electron–electron repulsion.

Dimer-Mott transition: A Mott transition occurring within molecular pairs (dimers) that act as correlated units.

Spin liquid: A magnetic state in which local moments remain disordered down to low temperatures due to frustration or quantum fluctuations.

Bechgaard salts: A family of organic conductors based on tetramethyltetraselenafulvalene (TMTSF) known for pressure-induced superconductivity.

κ-type geometry: A molecular arrangement in layer-structured organic salts characterised by a two-dimensional triangular lattice of dimers.

References

1. Organic quantum materials: A review. SmartMat (2023).
2. Structural Aspects of the Bechgaard and Fabre Salts: An Update. Crystals (2012).
3. Phase Competition and Superconductivity in κ-(BEDT-TTF)2X: Importance of Intermolecular Coulomb Interactions. Journal of the Physical Society of Japan (2017).