Small Charging Energies and g-Factor Anisotropy in PbTe Quantum Dots

ABSTRACT: PbTe is a semiconductor with promising properties for topological quantum computing applications. Here, we characterize electron quantum dots in PbTe nanowires selectively grown on InP. Charge stability diagrams at zero magnetic field reveal large even???odd spacing between Coulomb blockade peaks, charging energies below 140 ??eV and Kondo peaks in odd Coulomb diamonds. We attribute the large even???odd spacing to the large dielectric constant and small effective electron mass of PbTe. By studying the Zeeman-induced level and Kondo splitting in finite magnetic fields, we extract the electron g-factor as a function of magnetic field direction. We find the g-factor tensor to be highly anisotropic with principal g-factors ranging from 0.9 to 22.4 and to depend on the electronic configuration of the devices. These results indicate strong Rashba spin???orbit interaction in our PbTe quantum dots.

Automated summary

This study characterizes electron quantum dots in PbTe nanowires grown on InP, revealing unique electronic properties. The charge stability diagram shows large even???odd spacing and small charging energies, with Kondo peaks observed in odd Coulomb diamonds. By studying the energy levels and splitting under finite magnetic fields, highly anisotropic g-factor tensor and its dependence on electronic configuration are found, suggesting strong Rashba spin???orbit interaction in PbTe quantum dots.