Quantum Foundations

Research on quantum foundations was instrumental in the development of the fields of quantum information and computation – quantum cryptography, quantum teleportation and quantum computation all have roots in foundational thinking. In recent years, an opposite trend is developing. The skills gained in thinking about practical problems like computational speed up or secure communication are leading to insights about the nature of the theory itself. Ultimately, it is hoped that these insights will lead not only to new ways to explore quantum mechanics for information processing, but to a new conceptual understanding of the abstract formalism.

Two strategies adopted in this post-quantum-information foundational research are noteworthy. The first, a “bottom-up” approach, aims at identifying or formulating physical principles from which the abstract formalism of quantum theory can be reconstructed. This is the program of reconstructing quantum theory from foundational principles. The second, a “top-down” approach, aims at exploring theories that differ from quantum mechanics, and their information-processing capabilities, as “foils” to provide insights on what is special about quantum theory (and ultimately to provide insights for the bottom-up approach!). This is the program of generalised probabilistic theories.

This project aims at pursuing research questions motivated by these approaches. Specific topics include ontological models, generalised probabilistic theories, epistemic models, quantum reference frames, causal networks, Einstein-Podolsky-Rosen steering, quantum nonlocality and contextuality, closed timelike curves and nonlinear extensions of quantum theory.

Research Team:

Eric Cavalcanti
Stephen Bartlett