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Mott transition, antiferromagnetism, and unconventional superconductivity in layered organic superconductors

S. Lefebvre·P. Wzietek·S. Brown·C. Bourbonnais·D. Jerome·C. Meziere·M. Fourmigue·P. Batail
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Abstract

The phase diagram of the layered organic superconductor $κ$-(ET)$_{2}$Cu[N(CN)$_{2}$]Cl has been accurately measured from a combination of $^{1}$H NMR and AC susceptibility techniques under helium gas pressure. The domains of stability of antiferromagnetic and superconducting long-range orders in the pressure {\it vs} temperature plane have been determined. Both phases overlap through a first-order boundary that separates two regions of inhomogeneous phase coexistence. The boundary curve is found to merge with another first order line related to the metal-insulator transition in the paramagnetic region. This transition is found to evolve into a crossover regime above a critical point at higher temperature. The whole phase diagram features a point-like region where metallic, insulating, antiferromagnetic and non s-wave superconducting phases all meet.

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S. Lefebvre, P. Wzietek, S. Brown, C. Bourbonnais, D. Jerome, C. Meziere, M. Fourmigue, P. Batail. 2000-04-26. Mott transition, antiferromagnetism, and unconventional superconductivity in layered organic superconductors. https://doi.org/10.1103/physrevlett.85.5420

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