Pairing and vortex states in Sr2RuO4 studied by Hall probe magnetometry

Abstract Nature of the pairing and vortex states are studied in Sr 2 RuO 4 using a Hall probe array. No clear evidence for the spontaneous magnetic field, accompanying the time-reversal symmetry breaking states, has been obtained. Magnetization with H a ∥ c shows an anomaly close to H c2 and a peak near H a =0. We interpret the former to be due to the synchronization peak effect. H c1 or change in the vortex lattice structure could be relevant to the latter.