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
Werner Heisenberg was established by the "Max-Planck Gesellschaft" (MPG, Max Planck Society, successor organization to the "Kaiser-Wilhelm Gesellschaft"). Heisenberg was appointed president of the "Deutsche Forschungsrat". In 1951, the organization was fused with the Notgemeinschaft der Deutschen Wissenschaft (NG, Emergency Association of German Science) and that same year renamed the "Deutsche Forschungsgemeinschaft" (DFG, German Research Foundation). With the merger, Heisenberg was appointed to the presidium. In 1952, Heisenberg served as the chairman of the Commission for Atomic Physics of the DFG. Also that year, he headed the German delegation to the European Council for Nuclear Research (CERN). In 1953, Heisenberg was appointed