Biermann battery effect in laser-excited metals

Interaction of femtosecond optical pulses with solids is accompanied by inhomogeneous electron heating and interband transitions. In the general case it should lead to the excitation of bulk eddy currents due to the misalignment between the gradients of free electrons' pressure and density, similarly to the Biermann battery effect. We consider typical conditions for laser ablation of metals and show that these currents significantly heat electrons and provide convective heat transfer on subpicosecond timescales. Estimated heating depth reaches several hundred nanometers, which coincides with the ablation depth of metals at optical fluences of several $\mathrm{J}/\mathrm{c}{\mathrm{m}}^{2}$.