Explanation of Magnetic Destruction of Superconductor Using Schrodinger Equation in the Energy Space*** **, *** Accepted: **** **, *** Published (original) (raw)

EFFECT OF MAGNETIC FIELD ON SUPERCONDUCTING COMPLEX RESISTANCE ACCORDING TO QUANTUM MECHANICS

The expression of quantum resistance is used to express it as real and imaginary part in the presence of external magnetic field. The real part stands for superconducting resistance. The model indicates that when the external magnetic strength exceeds certain critical value superconductivity is destroyed because the resistance does not vanish. Keywords- Critical temperature superconductivity, zero resistance, plasma Equation.

QUANTUM RELATION BETWEEN SUPERCONDUCTIVITY RESISTANCE AND ENERFY GAP

When an external magnetic field applied on superconductor, the superconducting state is destroyed after the strength of magnetic field exceeds a certain critical value. This phenomenon can be explained on the basis of quantum resistance model. According to this model the critical magnetic field corresponds to the existence of an energy gap. The relation of this energy gap to the critical temperature resembles the conventional one. The existence of this gap can be explained on the basis of and Hubbard model.

Appendix E Theory of Superconductivity

2010

This appendix contains sections titled: London EquationsBardeen-Cooper-Schrieffer (BCS) TheoryHigh-Temperature Superconductor (HTS) Cuprates(Unconventional Superconductors)Heavy Fermion SuperconductorsType II SuperconductorsReferencesLondon EquationsBardeen-Cooper-Schrieffer (BCS) TheoryHigh-Temperature Superconductor (HTS) Cuprates(Unconventional Superconductors)Heavy Fermion SuperconductorsType II SuperconductorsReferences

UNDERSTANDING SUPERCONDUCTIVITY: A NEW APPROACH

As we know, in nature, nothing occurs unnecessarily, e.g., our hearts beat persistently without having any source of infinite energy, not unnecessarily; there is an important purpose as to why they beat persistently, and they have special structure, unlike simple balloons of blood, that keeps them beating persistently and provides all the properties our hearts possess. And therefore, as electrons, nucleons etc. all the particles possess persistent spin motion without having any source of infinite energy and several properties; there should positively be some important purpose as to why they possess persistent spin motion, and they should have special structure, unlike simple balloons of charge, that keeps them spinning persistently and provides all the properties they possess. Further, as all the phenomena/activities related with our hearts, e.g., continuous blood circulation etc. taking place in our bodies are the effects of the purpose behind persistent beating of our hearts and their special structure, similarly, all the activities/phenomena related with electrons, nucleons etc. taking place in their systems should be the effects of the purpose behind their persistent spin motion and their special structure. And therefore, presently, that purpose and the special structure of electrons have been determined. Their accounts enable to give very clear and complete explanation as to how resistance-less state, superconductivity, diamagnetism and all the properties exhibited by superconductors are generated, and Meissner effect, levitation of magnet above the superconductor and Josephson’s tunnelling take place in specimens at their transition temperature. Finally, it has also been explained as to how currently known some non-superconducting (e.g. ferromagnetic) substances can be made superconducting. In the current theories, no account of the above has been taken. And consequently, the BCS (Bardeen–Cooper–Schrieffer) theory, for which it is claimed that it accounts very well all the properties exhibited by the superconductors, if we examine it, we find numerous logically and practically unbelievable concepts have been taken to arrive at the desired results.

A QUALITATIVE OVERVIEW OF THE MECHANISMS OF SUPERCONDUCTIVITY SHAILAJ KUMAR SHRIVASTAVA

The mechanism of superconductivity continues to be one of the most fascinating and challenging topics in condense matter physics. The discovery of high-Tc cuprate superconductors and iron based superconductors has challenged the classical theories of condensed matter physics and opened a new chapter of strongly correlated electron systems. The key question of superconductivity is the nature of mechanism of pairing of carriers. The electron phonon interaction or spin fluctuations are considered to be central to the mechanism of superconductivity. In this article attempt has been made to highlights the brief outcome of various models and theories on the mechanism of superconductivity. I.Introduction Dutch scientist Heike Kammerlingh Onnes [1] discovered that electrical resistance of various metals e.g mercury, lead, tin and many others disappeared when the temperature was lowered below some critical value Tc. Meissner and Oschenfeld [2] observed that when a material is cooled in the presence of a magnetic field, on reaching its superconducting transition temperature (Tc) the magnetic flux is suddenly completely expelled from its interior. It means it exhibits perfect diamagnetism. Gorter [3, 4] put forward the idea of a two fluid model, in which the electron gas within the superconductor has two components. One component has no entropy and carries the supercurrent while the other component has all the entropy and behaves like a normal electron gas. Below the super conducting transition temperature, the superconducting electrons short out the normal electrons so that the electrical resistance is zero. These two features were captured in the equation proposed by London brothers [5], who first realized the quantum character of the phenomenon. Ginzburg and Landau [6] created a theory describing the transition between the superconducting and normal phases. Although the Ginzburg and Landau theory explained the macroscopic properties of superconductors, the microscopic properties remain unsolved. Bardeen, Cooper and Schrieffer created microscopic theory (BCS theory) [7] which describe conventional superconductors in the low temperature and low magnetic field regime. According to BCS theory, the superconductors at below Tc have an energy gap equal to binding energy of the Cooper pair, which dominates the transition temperature. The binding energy of the Cooper pair depends on the density of electron states at the Fermi surface, and on the strength of electron phonon interaction. High temperature superconductors are characterized by a layered two dimensional superconducting condensate and unique features that are very different from conventional superconducting materials. Recent studies [8, 9] reveal that the theoretical explanation for copper and iron superconductors could be the same and could even apply to other materials. The spin fluctuation mechanism of high-Tc superconductivity in copper oxide compound is determined by the high intensity of the antiferromagnetic exchange interaction. According to spin fluctuation mechanism [10], the pairing wave function of cuprate high-Tc superconductor should have d-wave symmetry. But unfortunately, some reports supported the d-symmetry for the high-Tc superconductors whereas others supported the s-symmetry. The survey of the mechanism of superconductivity [11] emphasized that all models used the conception of pairing with the subsequent formation of Bose-Condensate at Tc irrespective of the nature of the resulting attraction.