Observation of degenerate one-dimensional sub-bands in cylindrical InAs nanowires

TL;DR

This study experimentally observes and maps the 1D sub-bands in cylindrical InAs nanowires, confirming theoretical predictions and enhancing understanding of their electron transport properties at low temperatures.

Contribution

First experimental observation of degenerate 1D sub-bands in cylindrical InAs nanowires, validating simulation predictions and elucidating their energy structure.

Findings

Stepwise current increases with gate voltage indicate 1D sub-band transport.

Two-fold degeneracy in sub-band energies is experimentally confirmed.

Experimental sub-band energies match theoretical simulations.

Abstract

One-dimensional (1D) sub-bands in cylindrical InAs nanowires (NWs) are electrically mapped as a function of NW diameter in the range of 15-35 nm. At low temperatures, stepwise current increases with the gate voltage are clearly observed and attributed to the electron transport through individual 1D sub-bands. The two-fold degeneracy in certain sub-band energies predicted by simulation due to structural symmetry is experimentally observed for the first time. The experimentally obtained sub-band energies match the simulated results, shedding light on both the energies of the sub-bands as well as the number of sub-bands populated per given gate voltage and diameter. This work serves to provide better insight into the electrical transport behavior of 1D semiconductors.