Observation of a transverse Meissner effect in CuxTiSe2 single crystals

We report on local magnetization measurements showing the presence of an unexpectedly strong transverse Meissner effect in the superconducting CuxTiSe2 single crystals. We show that for tilted magnetic fields (Ha) vortices remain aligned with the ab planes up to field Hk∼Hp/sinθH (where θH is the angle between the applied field and the ab plane and Hp the first penetration field) and that for Ha>Hk, the field dependence of the vortex direction θB(Ha) can be well described assuming that vortices remain partially locked in the planes forming a staircase structure of average direction θB≠θH. These results indicate the existence of a strong modulation of the vortex core energy along the c axis but its origin remains unclear.