Selective area epitaxy of PbTe-Pb hybrid nanowires on a lattice-matched substrate

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

“…15 Recent work demonstrated the possibility to grow high-quality PbTe nanowires, either with vapor− liquid−solid epitaxy 16 or the selective-area-growth (SAG) technique. 15 Electrical characterization also demonstrated ambipolar characteristics, small charging energies and large gfactors. 17 Here, we investigate electron quantum dots in PbTe nanowires selectively grown on insulating InP substrates.…”

“…The SAG approach allowed investigation of quantum dots in nanowires with different crystal directions. Despite SAG of PbTe was only recently achieved, 15 we could identify gate configurations with electronic stability that allowed extensive characterization. Charging energies and single-particle excitation energies were extracted from charge stability diagrams.…”

“…The quest for realizing topological superconductivity in trivial semiconductors, with accompanying Majorana zero modes, would benefit from materials with strong spin–orbit interaction and large Landé g -factors. − In this context, PbTe may offer advantages compared to more established platforms such as InSb and InAs. Work on PbTe reported large and anisotropic g -factors, with absolute values up to 58 and strong spin–orbit interaction (SOI); both advantageous properties for the realization of sizable topological gaps at moderate magnetic fields. , PbTe, which is a well-known thermoelectric material, , also exhibits a direct band gap E g = 190 meV, electron effective masses of 0.024 m e – 0.24 m e , and a large dielectric constant ϵ r ∼ 1350 at low temperatures (compared to ϵ r ∼ 14 for InAs and InSb), which is expected to result in efficient screening of impurities and, consequently, high electron mobilities . Recent work demonstrated the possibility to grow high-quality PbTe nanowires, either with vapor–liquid–solid epitaxy or the selective-area-growth (SAG) technique .…”

“…Work on PbTe reported large and anisotropic g -factors, with absolute values up to 58 and strong spin–orbit interaction (SOI); both advantageous properties for the realization of sizable topological gaps at moderate magnetic fields. , PbTe, which is a well-known thermoelectric material, , also exhibits a direct band gap E g = 190 meV, electron effective masses of 0.024 m e – 0.24 m e , and a large dielectric constant ϵ r ∼ 1350 at low temperatures (compared to ϵ r ∼ 14 for InAs and InSb), which is expected to result in efficient screening of impurities and, consequently, high electron mobilities . Recent work demonstrated the possibility to grow high-quality PbTe nanowires, either with vapor–liquid–solid epitaxy or the selective-area-growth (SAG) technique . Electrical characterization also demonstrated ambipolar characteristics, small charging energies and large g -factors …”

Plateau regions for zero-bias peaks within 5% of the quantized conductance value $2e^2/h$

“…This work is from a single device whose quality is an improvement over our previous one [14]. Besides the 'end-to-end' correlation experiment to reveal gap-closing-reopening [39][40][41], future devices on 'single-terminal' experiments could aim at 1) looking for zero-bias peak-to-dip transition near 2e 2 /h with better tolerance [14,16,19]; 2) using a strongly dissipative probe to reveal quantized ZBPs and suppress non-quantized ones [42][43][44][45][46]; 3) looking for ZBP quantization in potentially better material systems [47,48]. The device conductance G as a function of V was directly calculated by dI/dV .…”