Heisenberg model (quantum) exhibits quasi-long range order. Heisenberg model (quantum) The Heisenberg model is a statistical mechanical model used in the study of critical points and phase transitions of magnetic systems, in which the spins of the magnetic systems are treated quantum mechanically. In the prototypical Ising model, defined on a "d"-dimensional lattice, at each lattice site, a spin formula_1 represents a microscopic magnetic dipole to which the magnetic moment is either up or down. Except the coupling between magnetic dipole moments, there is also a multipolar version of Heisenberg model called the multipolar exchange interaction. For quantum mechanical reasons (see exchange interaction
Max Planck Institute for Physics first head director. In October 1922, Max von Laue succeeded Einstein as managing director. Einstein gave up his position as a director of the institute in April 1933. The Institute took part in the German nuclear weapon project from 1939-1942. A year after the end of fighting in Europe in World War II, the institute was moved to Göttingen and renamed the Max Planck Institute for Physics, with Heisenberg continuing as managing director. In 1946, Carl Friedrich von Weizsäcker and Karl Wirtz joined the faculty as the directors for theoretical and experimental physics, respectively. In June 1942, Werner Heisenberg took