The Chinese military says it has invented quantum radar, a breakthrough which, if true, would render the hundreds of billions of dollars the United States has invested into stealth technology obsolete. Like the original invention of radar, the advent of modern artillery, or radio communications, quantum radar could fundamentally transform the scope and nature of war. ...Let me get this straight. The quantum radar entangles two photons, and fires one at the stealth plane. Then there is no need to look for any return signal because you can figure out what happened by examining the entangled photon that never left.
Quantum radar would exploit quantum entanglement, the phenomena that occurs when two or more particles are linked, even when separated by a significant amount of physical space. In theory, a radar installation could fire one group of particles towards a target while studying the second group of entangled particles to determine what happened to the first group. The potential advantages of this approach would be enormous, since it would allow for extremely low-energy detection of approaching enemy craft. Unlike conventional radar, which relies on an ability to analyze and detect a sufficiently strong signal return, quantum radar would let us directly observe what happened to a specific group of photons. Since we haven’t invented cloaking devices just yet, this would seem to obviate a great deal of investment in various stealth technologies.
China is claiming to have developed a single-photon radar detection system that can operate at a range of 100km, more than 5x that of a lab-based system developed last year by researchers from the UK, US, and Germany. Research into quantum radar has been ongoing for at least a decade, but there are significant hurdles to be solved.
This is impossible, of course. Either someone has some massive misunderstandings of quantum mechanics, or someone is perpetrating a scam. Or maybe China thinks that Americans are dumb enuf to believe a story like this.