Observation of Quantized Conductance in the Surface Bands of Bismuth Nanowires

TL;DR

This paper reports the experimental detection of quantized conductance in surface Rashba bands of bismuth nanowires, revealing high-mobility surface modes and their behavior under magnetic fields, advancing understanding of quantum transport in nanostructures.

Contribution

It provides the first experimental observation of quantized conductance in surface Rashba bands of bismuth nanowires, demonstrating mode behavior under magnetic fields.

Findings

Quantized conductance observed in Bi nanowires surface bands.

Multiple conductance plateaus with oscillatory thermopower detected.

High mobility surface modes consistent with Aharonov-Bohm interference.

Abstract

We report the experimental observation of quantized conductance by Rashba bands at the surface of 50-nm Bi nanowires. With increasing magnetic fields along the wire axis, the wires exhibit a stepwise increase of conductance with as many as four distinct plateaus together with oscillatory thermopower. The observations can be accounted for by the increase of the number of propagating surface modes. The modes have very high mobility and are associated with Aharonov-Bohm interference around the perimeter consistently with theory of quasiballistic one-dimensional nanowires considering that Lorentz forces decouple the modes from scattering at the nanowire surface.