Together with his colleague Lev Landau, Vitaly Ginzburg developed a phenomenological theory of superconductivity in the late 1940s. This theory proposes that those electrons that contribute to superconduction form a superfluid. The superconductor is described by a complex function called the order parameter, and indicates the fraction of electrons that has condensed into a superfluid.

	The Ginzburg-Landau order parameter is the solution of an equation similar to the quantum-mechanical wave equation.