Anomalous electron polarizability of HgTe quantum wells

The polarizability of electrons in CdTe/CdxHg1−xTe/CdTe quantum wells is studied. It is shown that polarizability in the quantum well without cadmium is negative, i.e., the displacement of an electron and hole in the main subbands of spatial quantization in an electric field applied perpendicularly to the quantum well plane is opposite to the force acting on it. It is predicted that the negative polarizability can reduce the dielectric constant of quantum wells by up to 15% and manifest itself as the blue shift of the interband light absorption edge in an electric field.