InSb Nanowires with Built-In GaxIn1-xSb Tunnel Barriers for Majorana Devices

TL;DR

This paper presents a method to engineer narrow tunnel barriers in InSb nanowires using GaxIn1-xSb segments, aiming to improve Majorana device performance by enabling more precise control of tunneling properties.

Contribution

It introduces a material-based approach to create and control sharp, narrow tunnel barriers within InSb nanowires through compositional and growth parameter adjustments.

Findings

Controlled synthesis of GaxIn1-xSb segments within InSb nanowires.

Quantitative extraction of barrier height and width from I-V measurements.

Potential for improved Majorana device performance with engineered barriers.

Abstract

Majorana zero modes (MZMs), prime candidates for topological quantum bits, are detected as zero bias conductance peaks (ZBPs) in tunneling spectroscopy measurements. Implementation of a narrow and high tunnel barrier in the next generation of Majorana devices can help to achieve the theoretically predicted quantized height of the ZBP. We propose a material-oriented approach to engineer a sharp and narrow tunnel barrier by synthesizing a thin axial segment of GaxIn1-xSb within an InSb nanowire. By varying the precursor molar fraction and the growth time, we accurately control the composition and the length of the barriers. The height and the width of the GaxIn1-xSb tunnel barrier are extracted from the Wentzel-Kramers-Brillouin (WKB)-fits to the experimental I-V traces.