Flat Bands for Quantum Metrology

Introduction

The ultimate limit on the accuracy of any measurement is set by quantum mechanics. This also means that quantum effects can be used in metrology and sensing to go well beyond any classical approach.

Classical vs Quantum Measurement

For classical systems, statistical error is proportional to ( \frac{1}{\sqrt{N}} ), with ( N ) being the number of measured particles. Measurements in quantum systems can overcome this limit and reach the Heisenberg limit, which is proportional to ( \frac{1}{N} ).

Challenges in Quantum Standards

However, quantum standards and sensors are challenging to put into practice, and their working conditions are nowadays intrinsically incompatible (e.g., magnetic field and superconductivity). This limitation affects their reach in terms of users and hinders their development as accurate and enhanced quantum technologies.

Vision of FLATS

The vision we propose in FLATS is to use twisted bilayer graphene as a multiphenomena platform to:

1. Develop present electrical quantum metrology standards that work under compatible conditions.
2. Create a new generation of metrological sensors that go beyond the International System of Units (SI).

Their common platform will allow for integration as a single multi-use on-chip quantum lab.

Implementation Strategy

To achieve this, we will:

1. Create a European twistronics platform for unprecedented control of the relative angular alignment between graphene/BN layers.
2. Develop novel and original quantum electrical standards with twisted heterostructures.
3. Enable the implementation of metrological sensors beyond the SI with our on-chip metrological quantum lab.

This will be the first step towards quantum-enhanced measurements for metrological applications.