Quantum measurements: Theory and applications

Project title: Quantum measurements: Theory and applications
Main applicant: Roope Uola, Division of Materials Theory
Grant amount: SEK 4 400 000 for the period 2025-2028

Quantum information processing promises various revolutionizing technologies. These include practical applications in, e.g., secure communication, quantum computing, and sensing. Typically, this so-called quantum advantage is attributed to the puzzling non-classical features of quantum states, i.e. carriers of quantum information, such as entanglement. Recently, a new approach has risen, that links the quantum advantage to the ways of reading out the information carriers, i.e. asking the right questions or performing the correct quantum measurements.

The novel approach relies on abstract connections between central classical-to-quantum borders given by quantum measurements, such as Heisenberg-type incompatibility, and those given by quantum correlations, such as the spooky action at a distance. Importantly, the latter is in the heart of various practical quantum advantages in, e.g., secure quantum communication and sensing.

The purpose of this project is to investigate the quantum advantage using quantum measurement theory. On the abstract side, new questions are investigated, such as which measurements are the most incompatible ones, and how to understand the quantum advantage quantitatively using quantum measurements. On the practical side, the project investigates novel quantum information processing scenarios, as well as reference-frame independent quantum correlations, which are relevant for ground-to-satellite quantum communication.