Laser-induced anisotropy of electronic pressure and excitation of edge currents inside metal.

We show theoretically that anisotropy of the electronic distribution function inside the laser-irradiated metal leads to the formation of edge currents at the timescale of distribution isotropization. When the electronic pressure in the skin layer is anisotropic, the pressure gradient appears to be non-potential force producing a low-frequency magnetic field. In the case of femtosecond laser pumping, the estimated internal magnetic field reaches magnitude up to 1 T even in the non-damaging interaction regime. We demonstrate that this field is localized inside the metal, while just a minor part of its energy is radiated into free space as a sub-terahertz signal.