Introduction of A New Principle in the Theory of Magnetism II. : New Statistical Thermodynamics for Magnetizable Materials and Superconductors

Abstract

A rigorous verification is made that the Meissner state has the minimum magnetostatic energy. The tricky structure of the magnetic energy is analyzed for a system comprised of two doubly connected superconductors, clarifying the profound meaning of the Zeeman energy and the Meissuer state. Through emphasizing the correct way of treating the magnetic energy of an externally applied field, a new thermodynamics for Curie-Langevin-Debye paramagnetism, for Larmor diamagnetism, and for superconductor has been developed. Since the thermodynamical energy of a many electron system cannot be identical to the Hamiltonian of the system, Miss. Van Leeuwen's theorem on the absence of diamagnetism in classical systems is wrong. The new thermodynamics allows easy derivation of the London equation and it gives a new way of understanding thermodynamically the normal-superconducting transition in a magnetic field.