Realization of Pristine and Locally-Tunable One-Dimensional Electron Systems in Carbon Nanotubes

TL;DR

This paper presents a novel method to create disorder-free, locally-tunable one-dimensional electron systems in carbon nanotubes, enabling precise control and new experimental possibilities in condensed matter physics.

Contribution

The authors develop a technique for deterministic, low-disorder, locally-tunable electron systems in carbon nanotubes with unprecedented control over electron localization and positioning.

Findings

Electrons can be localized at arbitrary positions along nanotubes.

Confinement potentials can be smoothly moved along the nanotube.

Transport characteristics show negligible effects of electronic disorder.

Abstract

Recent years have seen the development of several experimental systems capable of tuning local parameters of quantum Hamiltonians. Examples include ultracold atoms, trapped ions, superconducting circuits, and photonic crystals. By design, these systems possess negligible disorder, granting them a high level of tunability. Conversely, electrons in conventional condensed matter systems exist inside an imperfect host material, subjecting them to uncontrollable, random disorder, which often destroys delicate correlated phases and precludes local tunability. The realization of a condensed matter system that is disorder-free and locally-tunable thus remains an outstanding challenge. Here, we demonstrate a new technique for deterministic creation of locally-tunable, ultra-low-disorder electron systems in carbon nanotubes suspended over circuits of unprecedented complexity. Using transport experiments we show that electrons can be localized at any position along the nanotube and that the confinement potential can be smoothly moved from location to location. Nearly perfect mirror symmetry of transport characteristics about the centre of the nanotube establishes the negligible effects of electronic disorder, thus allowing experiments in precision engineered one-dimensional potentials. We further demonstrate the ability to position multiple nanotubes at chosen separations, generalizing these devices to coupled one-dimensional systems. These new capabilities open the door to a broad spectrum of new experiments on electronics, mechanics, and spins in one dimension.