For most of us, quantum physics feels like something that belongs in the invisible world of atoms and photons. It\u2019s the science of the very small, where particles can be in two places at once, or mysteriously linked across space. But scaling these phenomena up raises a pragmatic question: could they become too large (more or less) to hold in your hand and still exhibit a measurable quantum effect?<\/p>\n
At TU Wien, researchers have shown that the answer is yes. Focusing on a crystal as small as a centimeter of a strange metal, they saw clear signs of quantum entanglement<\/a> across not just single atoms but entire scales that an amorphous solid could describe.<\/p>\n In a paper published in Nature Physics, the authors present a tangible connection between commonly observed properties of materials and the fundamental quantum mechanics that underpin them.<\/p>\n Since the very beginning of quantum theory, there has been controversy over whether or not quantum effects occur in large objects. The original Schr\u00f6dinger\u2019s cat thought experiment was formulated to highlight the apparent absurdity of applying quantum rules to macro-sized objects.<\/p>\n But the TU Wien team took a different approach. \u201cWe do not try to bring the crystal as a whole into a superposition of two states,\u201d says Prof. Silke B\u00fchler\u2011Paschen from the Institute of Solid State Physics at TU Wien.<\/p>\n \u201cInstead, we ask whether its constituents are, collectively, in such a state of entanglement.\u201d<\/p>\n Instead of Schr\u00f6dinger\u2019s cat, she compares the phenomenon to an anthill: disturb one ant and its colony reacts as a unit. Analogously, particles entangled in the crystal do not just scatter as isolated entities; their response is organized by their quantum-interconnected states, a phenomenon that cannot be explained by classical physics.<\/p>\n