Terahertz photoconductivity in Hg$_{1-x}$Cd$_x$Te near the transition from the direct to inverted spectrum

For the Hg$_{1-x}$Cd$_x$Te-based structures, it is shown that the transition from the direct to inverted spectrum is accompanied by the sign change for the signals related to the terahertz photoconductivity and to the magnetophotogalvanic effect. Within the range of chemical compositions corresponding to the inverted spectrum, the photoconductivity kinetics exhibits specific features, which can result from the surface topological states.