Band Calculation Study of Metamagnetic Transitions of FeSi in Megagauss Field

The band structure of FeSi was studied by the ab initio band calculations explicitly including the applied field. We found that the magnetization process of FeSi has at least two step-like transitions and saturates above 1200 T. Here, we also present the magnetic field dependence of the calculated optical conductivity spectrum in the megagauss field region.