Anomalous flux entry into NbSe2

Abstract
Measurements of superconducting transitions of NbSe2 single crystals were performed. They allow the determination of the critical field for flux entry Hen and its angular dependence. An anomalous cusplike feature was observed which cannot be explained by anisotropic Ginzburg-Landau theory. A model is proposed which assumes easy directions for entering flux lines. Agreement with the measurements is good.