Probing of local electron states in Pb1−xSnxTe(In) narrow-gap semiconductors using laser terahertz radiation

A new type of semiconductor local states is revealed in Pb
_1-x
Sn
_x
Te(In) narrow-gap semiconductors. The energy position of these states is not linked to any specific location in the semiconductor energy spectrum, but follows the quasiFermi level position, which may be tuned by photoexcitation.