Feshbach Resonance

Feshbach resonance occurs when two atoms interact in such a way that an external magnetic field adjusts their energy levels, causing them to temporarily form a bound state. This resonance enhances their interaction strength, allowing precise control over atomic collisions. In ultracold gases, this technique is used to tune interactions, enabling exploration of quantum phenomena like superfluidity and the formation of molecules. Essentially, it acts like a switch, turning the atomic interactions up or down by adjusting the magnetic field, providing a powerful tool for manipulating matter at the quantum level.