PbTe—A new medium for quantum ballistic devices

Conductance quantization was measured in submicron mesa constrictions, patterned into PbTe/Pb0.92Eu0.08Te quantum wells of thickness 12, 25 and 50 nm. The main observation is almost unitary transmission of the one-dimensional quantum modes, despite of significant amount of charged defects in the vicinity of the constrictions. Such an extraordinary result is a consequence of the paraelectric properties of PbTe, namely, the suppression of long-range tails of Coulomb potentials due to the huge dielectric constant.