We present both static and time-resolved second harmonic generation (SHG) measurements on polar antiferromagnet Fe2Mo3O8 to monitor the evolution of the electric polarization change and its coupling to magnetic order. We find that only one of the second order tensor elements, χccc(2) ,shows a prominent change below the Neel temperature TN=60 K, indicating a magnetic order induced electric polarization change along the c-axis. Time-resolved SHG measurement reveals an ultrafast recovery of the second order tensor element upon the ultrashort laser excitation with fluence above 0.3 mJ/cm2, yielding evidence for a photoinduced ultrafast phase transition from the AFM ordered state to the paramagnetic state. Our work will help understand the spin induced polarization and the ultrafast optical tuning effect in Fe2Mo3O8.
@article{arxiv.2108.10258,
title = {Revealing magnetoelectric coupling effect in polar antiferromagnet Fe$_2$Mo$_3$O$_8$ by static and time resolved second harmonic generation},
author = {L. Y. Shi and D. Wu and T. Lin and S. J. Zhang and Q. M. Liu and Z. X. Wang and T. C. Hu and T. Dong and N. L. Wang},
journal= {arXiv preprint arXiv:2108.10258},
year = {2021}
}