Zhang, Y.; Ma, J.; Ikeda, K.; Hirata, Y.; Yamagami, K.; Schüßler-Langeheine, C.; Pontius, N.; Han, H.; Lin, Y.; Nan, C.; Wadati, H.: Photocarrier transport of ferroelectric photovoltaic thin films detected by the magnetic dynamics of adjacent ferromagnetic layers. Physical Review B 107 (2023), p. L220303/2-7
10.1103/physrevb.107.l220303
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Abstract:
We have observed photocarrier transport behaviors in BiFeO3/La1−xSrxMnO3 (BFO/LSMO) heterostructures by using time-resolved synchrotron x-ray magnetic circular dichroism in reflectivity. The magnetization of LSMO layers was used as a probe of photo-induced carrier dynamics in the photovoltaic BFO layers. During the photo-induced demagnetization process, the decay time of LSMO (x=0.2) magnetization strongly depends on the ferroelectric polarization direction of the BFO layer. The variation of decay time should be attributed to the different sign of accumulated photocarriers at the BFO/LSMO interface induced by the photovoltaic effect of the BFO layer. The photocarriers can reach the BFO/LSMO interface and influence the magnetization distribution in the LSMO layers within the timescale of ∼100 ps. Our results provide a novel strategy to investigate carrier dynamics and mechanisms of optical control of magnetization in thin film heterostructures.