What causes the lattice distortions in a superconductor?
A conducting solid, such as a metal, contains electrons which can move relatively freely through the background of positively charged ion cores. As an electron moves it exerts a Coulomb attraction on neighbouring ions and will distort the lattice structure locally. This is referred to as ‘electron-phonon interaction’. In some materials, at sufficiently low temperatures, this effect can lead to a dynamic pairing between electrons. This is believed to the mechanism behind superconductivity in most, but not all, superconductors. (The answers in the phonon and lattice distortion section were supplied by Prof Jaan Oitmaa.) Levitation of a magnet by a superconductor The magnetic field does not penetrate into a superconductor. This is called the Meissner effect. This effect together with conservation of the magnetic flux provides the levitation of a magnetic object above a superconductor or a superconductor above the magnet. When a magnet is brought near a superconductor, this exclusion of th
