Foreword to the Special Issue on Quantum Radar—Part 2

The articles in this special issue focus on the applications supported by quantum radar. QUANTUM physics has had a large impact on our everyday life. Relevant examples range from transistors and Monolithic microwave-integrated circuit, or MMIC,1 that make most of our technological society, as well as to nuclear energy, and to the science of materials. Some of these technologies have met with indisputable success while others have not proven to be useful to date. It should be remembered that the idea of a clean energy coming from nuclear fusion is an unfulfilled promise: such technologies have always involved a change of paradigm that made them quite different from known expectations. Note that Von Neumann machines, the foundations of our computers, are based on hardware made from quantum mechanics effects but they are otherwise easy to understand. A quantum computer is a rather different object and not so easy to comprehend unless an extensive knowledge of quantum physics is achieved. The same applies to the quantum radar (QR), the main topic of this special issue, which is quite different from a classical radar, both in terms of the working principles and the kind of hardware to realize it. The today’s radars are based on the propagation of electromagnetic waves of the classical (nonquantum) physics. The QR promises to be a radical change. It should be said that we are yet at a pioneering stage and we cannot be certain yet if a goal will be achieved nor in what form we will see it, though, R&D is progressing.