High bias transport and magnetometer design in open quantum dots

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 capable of measuring absolute magnetic field at micron scales with a noise floor of ∼110 nT/Hz at 300 mK. Non optimized measurements reported here are ∼2 orders of magnitude above this floor.