Superconductivity in an organic insulator at very high magnetic fields - art. no. 067002

We investigate by electrical transport the field-induced superconducting st ate (FISC) in the organic conductor lambda-(BETS)(2)FeCl4. Below 4 K, antif erromagnetic-insulator, metallic, and eventually superconducting (FISC) gro und states are observed with increasing in-plane magnetic field. The FISC s tate survives between 18 and 41 T and can be interpreted in terms of the Ja ccarino-Peter effect, where the external magnetic field compensates the exc hange field of aligned Fell ions. We further argue that the Fe3+ moments ar e essential to stabilize the resulting singlet, two-dimensional superconduc ting state.