  Understanding and manipulation of the laser processing quality during the
ablation of solids have crucial importance from fundamental and industrial
perspectives. Here we have studied the effect of external magnetic field on the
micro-material processing of silicon by ultrashort laser pulses. It was found
experimentally that such a field directed along the laser beam improves the
quality and efficiency of the material removal. Additionally, we observe that
the formation of laser-induced periodic surface structures (LIPSS) in a
multi-pulse regime is affected by the external magnetic field. Our results open
a route towards efficient and controllable ultrafast laser micromachining.
