Spin and Orbital Spectroscopy in the Absence of Coulomb Blockade in Lead Telluride Nanowire Quantum Dots

TL;DR

This study explores PbTe nanowire quantum dots, revealing their unique spin and orbital properties without Coulomb blockade interference, highlighting their potential for quantum computing applications.

Contribution

It demonstrates the absence of Coulomb blockade in PbTe quantum dots and characterizes their large, anisotropic g-factors and spin-orbit energies, advancing quantum device research.

Findings

No Coulomb blockade observed due to high dielectric constant

Large anisotropic g-factors between 20 and 44

Spin-orbit hybridization energies up to 600 μeV

Abstract

We investigate quantum dots in semiconductor PbTe nanowire devices. Due to the accessibility of ambipolar transport in PbTe, quantum dots can be occupied both with electrons and holes. Owing to a very large dielectric constant in PbTe of order 1000, we do not observe Coulomb blockade which typically obfuscates the orbital and spin spectra. We extract large and highly anisotropic effective Lande g-factors, in the range 20-44. The absence of Coulomb blockade allows direct readout, at zero source-drain bias, of spin-orbit hybridization energies of up to 600 microelectronvolt. These spin properties make PbTe nanowires, the recently synthesized members of group IV-VI materials family, attractive as a materials platform for quantum technology, such as spin and topological qubits.