High Bias Transport and Magnetometer Design in Open Quantum Dots

TL;DR

This paper investigates transport in open quantum dots, modeling electron temperature effects and proposing a quantum dot sensor for precise magnetic field measurements at micron scales with high sensitivity.

Contribution

It introduces a model linking bias-dependent transport to electron temperature and presents a novel quantum dot sensor for absolute magnetic field detection.

Findings

Transport measurements align with an effective electron temperature model.

The proposed sensor achieves a noise floor of approximately 50 μφ₀/√Hz at 300 mK.

The model explains Joule heating and electron cooling effects in quantum dots.

Abstract

We report transport measurements as a function of bias in open semiconductor quantum dots. These measurements are well described by an effective electron temperature derived from Joule heating at the point contacts and cooling by Wiedemann-Franz out-diffusion of thermal electrons. Using this model, we propose and analyze a quantum dot based sensor which measures absolute magnetic field at micron scales with a noise floor of $\sim 50 \mu\phi_{0} / \sqrt{Hz}$ at 300 mK.