In nanomagnets, there are domain walls — boundaries between regions with different magnetization. The authors placed two such walls inside an optical cavity and used a laser to create quantum entanglement: the oscillations of the walls became tightly correlated. Interestingly, the connection turned out to be stable at temperatures above millikelvins — previously such tricks required extreme cold. This approach brings us closer to building quantum devices that work under real-world conditions.
Inside a magnet, invisible boundaries run like strings stretched between zones of different magnetization. Placed in a mirror trap, these nanoscale strings are played by a 'bow' of light: light traveling at enormous speed pushes on them and makes them vibrate in harmony. The pressure of light synchronizes the trembling walls, turning them into a single quantum instrument.
Scientists have mastered precise control of the brightness and color of the trapped light, as well as the magnetic 'tension' holding the strings. As a result, the entanglement persists at temperatures a few thousandths of a degree above absolute zero—tens of times warmer than usual. The cavity acts as a supersensitive ear, picking up the quantum melody of the walls. This research continues Jeff Kimble's push toward larger quantum ensembles. A little more warmth, and such linked strings could be assembled into reliable qubits for quantum computing.
🎯 Quantum connections usually fear heat more than a snowman fears the summer sun. But these walls withstand temperatures up to 0.01 degrees above absolute zero. For scale: a typical experiment would require cold a hundred times harsher.
🎬 Like science fiction: entangled particles for instant interstellar communication are getting a real prototype.