Current-based RF charge sensing in a carbon nanotube
Abstract
Ultra-sensitive charge detection is a widely used tool for quantum electronics with applications in quantum information processing and in probing the physics of condensed matter systems. Existing approaches require either an impedance-matched resonant circuit, or millimeter-scale proximity between amplifier and sample, both adding complexity and constraining device design. In this work, we introduce a current-mode charge sensor in a suspended carbon nanotube, operating at the MHz resonance of an RLC tank circuit and achieving a charge sensitivity of . We utilize it to measure a double quantum dot (DQD) electrostatically defined in the same nanotube, revealing a highly regular charge stability diagram. We perform single-shot readout of the DQD charge state at an integration time of , without any false assignments over measurements and a signal-to-noise ratio of 17 exceeding the state of the art.
Cite
@article{arxiv.2607.28313,
title = {Current-based RF charge sensing in a carbon nanotube},
author = {Marta Cagetti and Stefan Forstner and Victor Champain and Roger Tormo-Queralt and Christoffer B. Møller and Sergio L. De Bonis and Chandan Samanta and Elsa Vázquez-Rodriguez and Eneko Mateos-Madinabeitia and David A. Czaplewski and Adrian Bachtold},
journal= {arXiv preprint arXiv:2607.28313},
year = {2026}
}