Two-band superconductivity in the doped spin ladder La1-xSrxCuO2.5

LaCuO2.5 is a system of coupled, two-chain, cuprate spin ladders which may be doped systematically by Sr substitution. Motivated by the recent synthes is of single crystals, we conduct a theoretical analysis to seek supercondu ctivity in this compound. We test this possibility within a model of spin f luctuation-mediated superconductivity, where the pairing potential is stron gly peaked at pi in the ladder direction. We solve the coupled gap equation s on the bonding and antibonding ladder bands to find superconducting solut ions across the range of doping, and discuss their relevance to the real ma terial. (C) 1999 Elsevier Science B.V. All rights reserved.