On the centenary of quantum mechanics — the bedrock of particle physics and enabler of numerous technologies – CERN is contributing to the development of a new generation of quantum technologies for fundamental research and beyond.
100 years ago, a handful of visionary physicists upturned notions about nature that had guided scientists for centuries. Particles can be point- or wave-like, depending on how you look at them. Their behaviour is probabilistic and can momentarily appear to violate cherished laws such as the conservation of energy. Particles can be entangled such that one feels the change of state of the other instantaneously no matter the distance between them, and, as befalls Schrödinger’s famous cat, they can be in opposite states at the same time.
Today, thanks to pioneering theoretical and experimental efforts to understand this complex realm, physicists can confidently navigate through such apparently irrational concepts. Quantum theory has not only become foundational to physics, chemistry, engineering and biology, but underpins the transistors, lasers and LEDs that drive modern electronics and telecommunications — not to mention solar cells, medical scanners and global positioning systems. But this is only the beginning.
On 7 June the United Nations declared 2025 the International Year of Quantum Science and Technology to celebrate the contributions of quantum science to technological progress, raise awareness of its importance to sustainable development, and ensure that all nations have access to quantum education and opportunities. As the world’s largest particle physics lab, CERN has been interrogating the quantum theories that govern the microscopic world for the past 70 years. Most recently, it has entered the rapidly growing domain of quantum technologies, which aims to harness the strangest aspects of quantum mechanics to build a new generation of quantum devices for fundamental research and beyond.
“In recent years, we have learned not just to use the properties of the quantum world but, also, to control them,” explains Sofia Vallecorsa, coordinator of the CERN Quantum Technology Initiative (QTI). “Today, the revolution is all about controlling individual quantum systems, such as single atoms or ions, enabling even more powerful applications.”
At CERN, quantum technologies are studied and developed through two different initiatives: the QTI, whose aim is to enable technologies – such as quantum computing, quantum state sensors, time synchronisation protocols, and many more – for high-energy physics activities; and the recently established Open Quantum Institute (OQI), whose aim is to identify, support and accelerate the development of future societal applications benefiting from quantum computing algorithms.
One of the most promising fields is quantum computing. Unlike classical computers that use “bits” that can be in one of just two states, quantum computers use qubits which can exist in superpositions of states. This enables a vast number of computations to be processed simultaneously, offering important applications in fields such as cryptography, logistics and process optimisation, and drug discovery. Quantum communication, which exploits the principles of quantum mechanics to make it impossible to intercept information without detection, is another significant area of development. A third pillar of CERN’s quantum-technologies programme is sensing to allow ultra-precise measurements of physical quantities, with potential applications in fields including medicine, navigation and climate science.
“What started 100 years ago as a purely theoretical physics investigation is now beginning to unleash its full potential,” says OQI coordinator Tim Smith of CERN. “The International Year of Quantum Science and Technology will be a wonderful opportunity to celebrate the past, the present and the future of our understanding of the quantum world.”