Quantum resource theories

Project description

The emergence of quantum information theory in the last three decades has led to a crucial reassessment of quantum effects such as superposition and entanglement: from poorly understood and even paradoxical concepts, these are now regarded as fundamental ingredients to achieve tasks otherwise impossible within the realm of classical physics, thus enabling a wealth of innovative technologies. At the core of this revolution lies the formalisation and characterisation of such phenomena as physical resources. Initiated with quantum entanglement, and successfully applied e.g. to purity, coherence [1], and informational nonequilibrium in thermodynamics, this application-driven viewpoint motivates the formulation of resource theories, that is, quantitative theories capturing the resource character of physical traits in a mathematically rigorous fashion. General studies on resource theories have shown that all quantum states which do not belong to a convex subset of "free" states can be regarded as resources, in the sense that they provide a quantifiable advantage in operational tasks such as channel discrimination [2].

This project aims to advance the current frontiers of knowledge on resource theories for quantum phenomena and physics more broadly. In particular, possible directions include:

Develop foundations and applications of dynamical resource theories, where the operations rather than the quantum states are scrutinised for their usefulness in information technology tasks, and investigate theories of multiple competing resources.

Tailor resource theories to realistic experimental settings (e.g. in sensing and imaging instruments) and determine the achievable advantage under physical constraints imposed by energy limitations, actual cost of components or external noise influences.

Apply results from resource theories to draw conclusions on fundamental limitations of physical processes, e.g. to characterise the structure of thermodynamics from macro- to nano- and quantum scale, and the ultimate limits of intelligence in generalised probabilistic theories.