Next Thursday, October 30th, Professor Artur Ekert from the University of Oxford will give the new SO-IFIC colloquium. In this talk, we will have the opportunity to learn more about a set of mathematical relationships known as the 'Bell inequalities'.

Proposed by John Bell in 1964 to test the completeness of quantum theory, Bell inequalities were long regarded as philosophical curiosities. The first experimental violations attracted little attention, as most physicists focused on the predictive success of quantum mechanics rather than its interpretation. In 1991, Bell inequalities were reformulated as a tool to detect eavesdropping in cryptography, leading to the concept of device-independent quantum key distribution—secure communication certified by quantum nonlocality itself. This new perspective revitalized quantum foundations and stimulated experimental efforts to close all loopholes in Bell tests. What began as an almost philosophical quest has become the cornerstone of the most advanced cryptographic systems proposed to date.

Today, Bell inequalities demonstrate that there is no theory of local hidden variables capable of reproducing quantum predictions. Experiments have confirmed the violation of these inequalities, supporting the counterintuitive and nonlocal nature of quantum entanglement.

Artur Ekert is one of the pioneers of quantum information science. His invention of entanglement-based quantum cryptography has linked the fundamental concepts of quantum theory with the study of secure communication. He has made several foundational contributions to both the theoretical and experimental aspects of quantum communication and computation.

In addition, Professor Ekert is the founder of the Centre for Quantum Technologies in Singapore and has received various awards, such as the Maxwell Medal from the UK Institute of Physics and the Hughes Medal from the Royal Society of London, of which he is a member.

Outside academia, Professor Ekert is a passionate diving instructor and a pilot.

This colloquium is part of the CEX2023-001292-S grant, funded by MICIU/AEI/10.13039/501100011033.

More information about the event can be found at this link.