Molecular Magnets Catch Dark Matter express
Dark matter is invisible, but according to calculations, it holds galaxies together. Catching its particles is like hearing a whisper in a noisy room. You need a material that responds loudly and noticeably to the slightest nudge.
Molecular magnets could be such a material — substances where each molecule acts as an independent tiny magnet. Unlike ordinary magnets, their magnetic properties depend on individual molecules and can be tuned chemically. Scientists considered two types of such molecules — based on dysprosium and manganese. When a dark particle (for example, a dark photon or an axion) hits such a molecule, it imparts energy. The molecule flips, and this flip triggers a chain reaction: neighboring molecules also flip, like dominoes. This "magnetic avalanche" releases a measurable amount of energy.
The new approach promises to be more than ten times more sensitive than existing detectors for some dark matter models. It's like swapping an ear for a sensitive microphone: a whisper that was once lost becomes audible.
So chemistry helps physics: by assembling molecules with the right properties, we can build detectors for the most elusive particles in the universe.
Dysprosium is a rare-earth metal used in the strongest magnets, such as those in wind turbines. Manganese, on the other hand, is part of enzymes that protect cells from oxidation.
The idea of catching dark matter with sensitive materials echoes the detectors from Liu Cixin's novel "The Dark Forest," where unusual physical effects are used to detect invisible threats.