Quantum locking, also known as quantum levitation or magnetic levitation, is a phenomenon in which a superconductor can be trapped in a stable position above a magnet without any physical contact or support. It is a remarkable demonstration of the unique properties of superconductors and their interaction with magnetic fields.
Superconductivity is a quantum mechanical phenomenon that occurs in certain materials at very low temperatures. When a material becomes superconducting, it can conduct electric current without any resistance. One of the key features of superconductors is their ability to expel magnetic fields from their interior. This is known as the Meissner effect.
In the case of quantum locking, a superconductor is cooled to a temperature below its critical temperature, and then it is placed above a magnet. When the superconductor is sufficiently cooled, it enters a state known as the superconducting state, and it develops a perfect diamagnetic response. This means that it generates a magnetic field that perfectly cancels out the external magnetic field from the magnet.
Due to this perfect diamagnetic response, the superconductor experiences a phenomenon called flux pinning. The magnetic field of the superconductor effectively locks onto the magnetic field of the magnet, creating a stable levitation effect. The superconductor hovers above the magnet, maintaining a fixed position, even if it is tilted or moved.
This locking effect is often demonstrated by placing a small superconducting disc, known as a superconductor puck, above a magnet. Once the superconductor is cooled and brought near the magnet, it locks in position and can even support the weight of small objects placed on top of it. The levitation appears to defy gravity and is a fascinating example of the principles of quantum physics in action.
Quantum locking has potential applications in various fields, including transportation systems, energy storage, and high-speed trains, where the lack of friction could lead to significant efficiency gains. However, practical implementation is currently limited by the need for extremely low temperatures and the delicate nature of superconducting materials.