  N\'eel spin-orbit torque allows a charge current pulse to efficiently
manipulate the N\'eel vector in antiferromagnets, which offers a unique
opportunity for ultrahigh density information storage with high speed. However,
the reciprocal process of N\'eel spin-orbit torque, the generation of ultrafast
charge current in antiferromagnets has not been demonstrated. Here, we report
the experimental observation of charge current generation in antiferromagnetic
metallic Mn2Au thin films using ultrafast optical excitation. The ultrafast
laser pulse excites antiferromagnetic magnons, resulting in instantaneous
non-equilibrium spin polarization at the antiferromagnetic spin sublattices
with broken spatial symmetry. Then the charge current is generated directly via
spin-orbit fields at the two sublattices, which is termed as the reciprocal
phenomenon of N\'eel spin-orbit torque, and the associated THz emission can be
detected at room temperature. Besides the fundamental significance on the
Onsager reciprocity, the observed magnonic charge current generation in
antiferromagnet would advance the development of antiferromagnetic THz emitter.
