2016 Dirac Medal and Prize of the Institute of Physics

Professor Sandu Popescu, University of Bristol, for his fundamental and influential research into nonlocality and his contribution to the foundations of quantum physics.

Picture of Sandu Popescu

Professor Sandu Popescu has made fundamental and influential advances in our understanding of quantum physics.

As well as providing deep insight into the foundations, he has made seminal contributions to the fields of quantum information and computation, and he continues to advance the international effort in these areas.

Popescu’s research is particularly noteworthy for his ability to ask new questions and identify new issues, meaning that he has made deep contributions to a broad range of subjects.

Many of his major achievements are in connection with quantum nonlocality, which was once considered exotic or even paradoxical. Popescu identified nonlocality as a defining aspect of quantum mechanics and as central to quantum information. Far from being an esoteric feature exhibited by carefully chosen states, quantum nonlocality is generic – almost every quantum state of two or more particles is non-local.

Popescu has been influential in investigating the manipulation and quantitative description of nonlocality. His work on the possibility of manipulating nonlocality has played a crucial role in developing the modern view of nonlocality as a resource that, like energy, can be stored, transformed, and consumed while performing useful tasks. This research led Popescu to develop a scheme for quantum teleportation, and he collaborated in the first experimental realisation of this phenomenon.

He has also provided a framework for understanding multi-particle non-locality – proving that there are infinitely many different irreducible types of nonlocality – and, in collaboration with Daniel Rohrlich, identified the Popescu-Rohrlich correlations, which are now regarded as the basic unit of nonlocality.

He has also deepened our understanding of quantum thermodynamics – demonstrating that almost all subsystems are canonical, and that thermal equilibrium is reached for almost all initial states. Popescu’s work in this area led him to the theoretical construction of the smallest possible refrigerator, which has garnered much interest from both the scientific community and the public.

Popescu’s intellectual interests range from speculations close to philosophy, through concepts and technicalities of theoretical physics, to the design of experiments and patented applications. His engaging and informal lectures inspire audiences at all levels.