Related papers: Meissner effect, diamagnetism, and classical physi…
A recent study (arXiv:1109.1968v2, to be published in American Journal of Physics) claims to provide a classical explanation of the Meissner effect. However, the argument misuses de Gennes' derivation of flux expulsion in superconductors.
The Bohr-van Leeuwen theorem is often summarized as saying that there is no classical magnetic susceptibility, in particular no diamagnetism. This is seriously misleading. The theorem assumes position dependent interactions but this is not…
The question of how a metal becoming superconducting expels a magnetic field is addressed. It is argued that the conventional theory of superconductivity has not answered this question despite its obvious importance. We argue that the…
We point out that the Meissner effect, the process by which a superconductor expels magnetic field from its interior, represents an unsolved puzzle within the London-BCS theoretical framework used to describe the physics of conventional…
Theory and experiment on the London moment is reviewed. A simple mathematical model is motivated and then used to study the responses of a spherical superconductor to an external field and to rotation. It reveals a connection between…
It is generally accepted that the most fundamental property of a superconductor is that it exhibits the Meissner effect. Of similar importance is the Becker-London effect, i.e. generation of magnetic field inside a rotating superconductor.…
The thermodynamic principle of superfluid flow -- that the energy is minimized at constant entropy -- is applied to superconducting currents to derive the Meissner-Ochsenfeld effect in which magnetic fields are expelled from…
A theorem on the magnetic energy minimum in a perfect, or ideal, conductor is proved. Contrary to conventional wisdom the theorem provides a classical explanation of the expulsion of a magnetic field from the interior of a conductor that…
The Meissner effect, the expulsion of magnetic field from the interior of a metal entering the superconducting state, is arguably the most fundamental property of superconductors, discovered in 1933. The conventional theory of…
The original formulation of the Bohr-van Leeuwen (BvL) theorem states that, in a uniform magnetic field and in thermal equilibrium, the magnetization of an electron gas in the classical Drude-Lorentz model vanishes identically. This stems…
Alfven's theorem states that in a perfectly conducting fluid magnetic field lines move with the fluid without dissipation. When a metal becomes superconducting in the presence of a magnetic field, magnetic field lines move from the interior…
The most general electrodynamic equations of a perfect conducting state are obtained using a variational principle in a classical framework, following an approach by Pierre-Gilles de Gennes. London equations are derived as the…
An electric current generates a magnetic field, and magnetic fields cannot exist in the interior of type I superconductors. As a consequence of these two facts, electric currents can only flow near the surface of a type I superconducting…
The Meissner effect is the expulsion of magnetic flux from the interior of a bulk superconductor in the presence of the constant critical magnetic field by the persistent current circulating near the surface of the superconductor. The…
We prove a theorem on the magnetic energy minimum in a system of perfect, or ideal, conductors. It is analogous to Thomson's theorem on the equilibrium electric field and charge distribution in a system of conductors. We first prove…
It is shown that the superconducting energy gap necessarily lead to the disappearance of some quasi-electrons, thus we suggest a new boson-fermion Hamiltonian to describe superconductivity. The new supercurrent equations are derived with…
The Meissner effect and the Spin Meissner effect are the spontaneous generation of charge and spin current respectively near the surface of a metal making a transition to the superconducting state. The Meissner effect is well known but, I…
It is generally known that the orbital diamagnetism of a classical system of charged particles in thermal equilibrium is identically zero -- the Bohr-van Leeuwen theorem. Physically, this null result derives from the exact cancellation of…
The discovery of the Meissner effect was a turning point in the history of superconductivity. It demonstrated that superconductivity is an equilibrium state of matter, thus allowing to use thermodynamics for its study. This provided a…
Momentum and energy conservation are fundamental tenets of physics, that valid physical theories have to satisfy. In the reversible transformation between superconducting and normal phases in the presence of a magnetic field, the mechanical…