Magnetotransport study of the pressure-induced antiferromagnetic phase in FeSe

The resistivity $\rho$ and Hall resistivity ${\rho }_H$ are measured on FeSe at pressures up to $P$ = 28.3 kbar in magnetic fields up to $B$ = 14.5 T. The $\rho (B)$ and ${\rho }_H(B)$ curves are analyzed with multicarrier models to estimate the carrier density and mobility as a function of $P$ and temperature ($T⩽$ 110 K). It is shown that the pressure-induced antiferromagnetic transition is accompanied by an abrupt reduction of the carrier density and scattering. This indicates that the electronic structure is reconstructed significantly by the antiferromagnetic order.