1925 is generally regarded as the birth year of quantum mechanics, as essential fundamental ideas of this theory were put forward at that time by Heisenberg, Born, Jordan and Schrödinger. This year we celebrate the centenary of what many consider to be the most successful theory in the history of physics. Quantum mechanics not only provided us an understanding of the inner workings of matter, laid the foundation for transformational technologies such as modern electronics, opto-electronics and lasers, but keeps driving progress in the vast field of modern quantum technologies.

Quantum technologies leverage quantum mechanical effects to tackle challenges only solvable by exploiting and controlling quantum properties at microscopic and macroscopic scales. They represent one of the most thriving directions in physics, leveraging a wide collection of breakthroughs in quantum science to tackle some crucial problems in technology and potentially society. Quantum technologies bring together not only physics, but a wider range of areas including materials science, mathematics, chemistry, engineering, and computer science, becoming a widely interdisciplinary area. Quantum technologies have expanded into a wide range of domains and sub-fields such as (i) quantum sensing and metrology, (ii) quantum computing, algorithms and simulation, (iii) quantum materials, and (iv) quantum communication.

In this collection of articles, we aim to provide a sample of the depth, impact, and diversity that quantum technologies have evolved into in recent years. We start with a historical summary and move towards covering different quantum technology sub-areas in a set of representative overview articles. Needless to say, this collection cannot do justice to the breadth of all the activities in this field. This special issue starts with Blum describing the origin of the mathematical formulation of quantum mechanics. Bernabeu considers the wave-particle duality arising in quantum mechanics. Breakthroughs and challenges in the theory of superconducting quantum materials are discussed by Black-Schaffer et al. Solid-state quantum devices based on GaAs and graphene are reviewed by Ensslin. The current state in long-distance quantum communication is reviewed by Weinfurter. Stiller’s article describes the engineered collective interactions of photons and with acoustic excitations in solids for optoacoustic signal processing. Meijer et al. show how quantum mechanical effects are leveraged for highly sensitive sensors. The work by Nieuwenhuizen investigates the didactics of quantum measurements for schools and universities. Finally, a gamification of quantum science is presented by Parisi, Marino and Mosca in a card game that mimics the phenomenon of entanglement.

Even hundred years after the establishment of its foundations, quantum technologies are still in their infancy, making them a rapidly evolving area in science and technology. Most importantly, their development has and will impact a wide variety of areas of science. Quantum detectors can help detecting dark matter and quantum gravity or provide groundbreaking new forms of medical imaging. The development of noisy quantum computers has promoted advances in quantum-inspired classical algorithms, and potential future topological qubits could enable large-scale quantum algorithms. Topological and superconducting quantum materials may contribute to a drastic reduction in energy consumption in information technologies. Entangled photon communication may provide the most robust strategy for long-range protected communication. Finally, and perhaps most importantly, some new applications, that we have not even considered at this point, may arise as progress goes on in the different sub-areas.

Experiments that were considered impossible just 20 years ago have become now the standard. Ideas that were merely theorists’ proposals are now routinely demonstrated in laboratories. Quantum is now far beyond being just an exciting field of research but has become a key strategic technology worldwide, also in Europe. Basic research, infrastructures, businesses and education form the fundamental pillars of quantum technologies. While it is impossible to predict their ultimate impact in the future, quantum technologies will certainly transform our society by addressing some of the currently unsolvable challenges.

We hope you enjoy reading this collection of articles.

© European Physical Society, EDP Sciences, 2025