WP1: Devices and experimental techniques for single-electron quantum optics

The aim of this work package is to develop novel semiconductor devices and to provide the essential experimental technique for the realisation of single-electron interferometry and quantum state tomography. The tasks in this work package will serve to establish the key prerequisites to enable the use and application of single-electron wave packets, by fabricating and characterising the quantum optics components, testing their interoperability and validating the basic functionality of the final integrated circuits.

WP2: Metrological tools for single-electron wave packets

The aim of this work package is to develop experimental techniques and devices for detecting and characterising single-electron wave packets. The resulting new metrological tools for single-electron wave packets will be applied to measure and optimise the wave packet time/energy properties. The work package will provide optimised wave packet sources and single-electron wave packet read-out for use in single-electron wave packet interferometers for quantum metrology in WP3. Additionally, it will provide the experimental basis for developing quantum tomography and quantum enhanced sensing concepts in WP4. WP2 will be based on the devices and experimental techniques from WP1, and it will feedback to WP1 to enable iterative improvements of the developed experimental techniques.

WP3: Single-electron wave packet interferometers for quantum metrology

The aim of this work package is to develop on-demand single-electron interferometry for local electric and magnetic field measurements with high temporal resolutionand for the characterisation of single-electron phase coherence. Two interferometer-geometries of the Mach-Zehnder and Fabry Perot types will be examined. Single on-demand electron wave packets will be sent to the interferometer. The interference is sensitive to the influence of electric and magnetic fields, resulting in a phase dependent probability for transmission into the exit channels and this will be read out as an average current or by single electron wave packet detection. Pursuing the three stated combinations of interferometer and readout type will allow the consortium to find the best solution for the quantum sensor application.

WP4: Concepts and theoretical tools for quantum metrology

This work package consolidates the theoretical and model development activities from this project. The aims of WP4 are threefold: to support the design of device components and the optimisation of control sequences for electron quantum optics by modelling specific setups and protocols, to develop concepts and theoretical tools for a full quantum state tomography, and to establish the theoretical framework for single‑electron interferometry and tomography as a metrological tool.

WP5: Creating impact

The aim of this work package is to communicate information about the project and its outcomes/consequences to the relevant end-users, supporting an emerging community of researchers with expertise in the metrology of quantum technologies.