Terahertz radiation from antiferromagnetic MnO

摘要

We have observed terahertz radiation from antiferromagnetic MnO excited by femtosecond laser pulses. The oscillations following the main pulse are radiation from optically excited antiferromagnetic magnons. The origin of the main pulse radiation can be attributed to second-order nonlinear optical effects in bulk and/or at surface with antiferromagnetic spin order.