Quantum phenomena are usually associated with extremely small objects such as individual atoms, molecules, or photons that must be carefully isolated from their surroundings. But can those same strange quantum effects also exist in objects large enough to see and hold?
Researchers at TU Wien have now provided compelling evidence that they can. By studying a centimeter-sized crystal made from a type of material known as a strange metal, the team detected a high degree of quantum entanglement, one of the most remarkable features of quantum physics. They accomplished this using a technique from quantum information science called quantum Fisher information.
The results create a new connection between quantum information and solid-state physics by showing that quantum entanglement can be measured directly in a macroscopic strange metal.
From Schrödinger's Cat to an Anthill
Whether quantum mechanics applies only to tiny particles or also to larger objects has been debated since the early days of the field. Physicist Erwin Schrödinger famously illustrated the mystery with his thought experiment involving a cat that is simultaneously alive and dead until observed. Since then, scientists have repeatedly pushed the limits of how large a system can display quantum behavior.
