Possible influence of two-band superconductivity on the behaviour of the second magnetization peak in La2−xSrxCuO4 single crystals

An anomalous temperature T dependence of the field Hon for the onset of the second magnetization peak (SMP) in La1.81Sr0.19CuO4 single crystals (with the external magnetic field H oriented parallel to the c axis) is discussed. While the peak field Hp and the magnetization at Hp have a continuous variation with T, Hon exhibits a sudden decrease with increasing T for T ∼ 11 K-15 K. The analysis of the nature of the SMP in La2−xSrxCuO4 single crystals in terms of a simple dynamic energy balance relation suggests that the observed behaviour could be related to the particular T dependence of the superfluid density in the case of two-band superconductivity, affecting the T variation of the elastic energy of the vortex system at low H.