De Haas–Van Alphen effect

The De Haas–Van Alphen effect, often abbreviated to DHVA, is a quantum mechanical effect by which the magnetic susceptibility of a pure metal crystal oscillates as the intensity of the magnetic field B is increased. It can be used to determine the Fermi surface of a material.

Source: Wikipedia — De Haas–Van Alphen effect (CC BY-SA 4.0)