Course summary

We are currently witnessing the dawn of a Quantum Technology revolution in which fundamental physical phenomena such as entanglement and superposition are harnessed for ground-breaking applications in computation, secure communication, sensing and metrology and machine learning. Over the last century, quantum mechanics has brought unprecedented progress in understanding the laws of nature at the microscopic level, from the early discoveries of energy quantisation and photoelectric effect, to the development of the standard model of elementary particles. This has culminated with theories such as superconductivity and the quantum Hall effect, and experimental breakthroughs such as the discovery of the Higgs boson and the realisation of Bose-Einstein condensates. To celebrate this landmark, the United Nations has declared 2025 to be the international year of Quantum Science and Technology. As scientists developed more and more sophisticated tools for measuring and controlling quantum systems, they came to think of individual systems like atoms and photons as carriers of a new type of information. For instance, an electron spin pointing up or down, or a photon being left or right polarised, are examples of what we now call qubits, quantum analogues of bits of information. However, unlike their classical analogues, qubits can exist in a superposition of the two states and can exhibit uniquely quantum correlations called entanglement. In particular, the discovery by John Bell that quantum reality cannot be described in classical terms was a catalyst for renewed interest in foundational research, which led to the development of Quantum Information and Quantum Computation. This field focuses on understanding the rules for processing quantum information and how this relates to classical fields such as computing, information theory, statistics and control. This new perspective led to truly revolutionary discoveries ranging from faster computing to secure communication, and high precision sensing. These developments are expected to have a great impact on large parts of the economy. Quantum technology has taken up the challenge to put these ideas into practice to build the:

• first quantum computers

• quantum enhanced sensors

• quantum communication networks

• gravitational wave detectors