Sunlight Creates Quantum Entanglement ⚡ экспресс
Energy consumption is a major obstacle for quantum technologies, especially in photonics, where high-coherence lasers are traditionally used. It has been experimentally proven that natural incoherent sunlight can generate entangled photons through spontaneous parametric down-conversion (a process in which one photon splits into two correlated ones). The measured degree of entanglement (concurrence 0.905) and state fidelity (0.939) are comparable to laser-based setups, and the violation of Bell's inequality (S=2.54 with a classical limit of 2) confirms the quantum nature. An unexpected twist: the chaotic light of the Sun could replace expensive 'quantum optics' in remote missions, reducing energy costs.
Sunlight is a turbulent stream carrying inseparable pairs of droplets. That’s what quantum entanglement looks like: two particles are so connected that a fluctuation in one instantly resonates in the other. In the past, creating such pairs required a 'calm pool' — a perfectly tuned laser beam. But scientists took ordinary sunlight (the very light rushing toward us at the speed of light) and passed it through a splitting crystal, which, like a waterwheel, divided the stream into pairs of entangled particles.
Light sensors using photometry showed near-perfect synchrony. The classic test proposed by Bell and refined by Aspect and Zeilinger confirmed genuine quantum behavior — with no hint of classical trickery. The wild stream performs as well as the calm pool.
Surprise: all it takes is a drop from the stream — the Sun gives billions of times more light per second than all quantum networks would ever need. A Mars rover could entangle particles at sunset, no lasers required. This fits into the quantum picture of the world and promises cheap quantum communication.
🎯 Every second, the Sun radiates billions of times more light than needed to run all existing quantum networks.
🎬 Like in science fiction: a Martian colony might one day exchange entangled signals with Earth using nothing but daylight.