Quantum limit and reentrant superconducting phases in the Q1D conductor Li0.9Mo6O17

We solve the theoretical problem of restoration of superconductivity in a triplet quasi-one-dimensional, layered superconductor in an ultra-high magnetic field. With the field perpendicular to the conducting chains as well as having a component normal to the layers, we suggest a new quantum limit superconducting phase and derive an analytical expression for the transition temperature as a function of magnetic field, T⁎(H)T⁎(H). Using our theoretical results along with the known band and superconducting parameters of the presumably triplet superconductor Li0.9Mo6O17, we determine the orientation of HH that maximizes T⁎(H)T⁎(H) for a given value of the field. Subsequently, we show that reentrant superconductivity in this compound is attainable with currently available non-destructive pulsed magnetic fields of order H≃100T, when such fields are perpendicular to conducting chains and parallel to the layers. For its possible experimental discovery, we give a detailed specification on how small angular inclinations of the magnetic field from its best experimental geometry decrease the superconducting transition temperature of the reentrant phase.