Josephson vortex state across the phase diagram of La2-xSrxCuO4:: A magneto-optics study -: art. no. 054503

We present a detailed doping dependent study of the Josephson vortex state in La2-xSrxCuO4 using infrared spectroscopy. A magnetic field as high as 17 tesla, applied along the CuO2 planes, is found to suppress the Josephson plasmon in all measured samples. We find the strongest suppression in samples with dopings close to x=1/8 and attribute this effect to the spontaneous formation of in-plane charge inhomogenities at this doping level. Several theoretical models of the Josephson vortex state are applied to explain the observed effects.