The phenomenon of superconductivity, in which the electrical resistance of certain materials completely vanishes at low. These work because a superconductor repels a magnetic. Superconductivity is a unique and powerful phenomenon of nature. It occurs in a wide variety of metals and alloys, below a transition temperature tc which currently ranges up to. The temperature at which the transition took place was called the critical temperature tc.
The central feature of the bcs theory is that two electrons in the superconductor are able to form a bound pair called a cooper pair if they somehow experience an attractive interaction between. Lecture notes on superconductivity a work in progress. Earlier, only metals and their alloys at very low temperatures 0 to 15 k were known to behave as superconductors. Superconductivity article about superconductivity by the. In our days of lively speculations on possible causes of superconductivity it should provide the newcommer to the. To take full advantage of the attractive potential illustrated in fig. Bill coish introduction superconductivity refers to a complex of phenomena which are usually found to occur together. Superconductivity is destroyed by either raising the temperature or by applying a magnetic eld. Introduction of superconductivity electrical resistivity v temp. Yet their limitations are also very straightforward. Yet the 1955 simple facts of superconductivity capture the great qualitative change that occurs in the transition to the superconducting state. A description of superconductivity in a little more detail than you need at a level to explain the basic concepts of a quantum mechnical phenomenon. Unit v superconductivity engineering physics when the super conducting ring temperature cooled less than of it s critical temperature, it obeys meissner effect.
It is important to note that this linear relationship between m and h does. Superconductivity is the set of physical properties observed in certain materials, wherein electrical resistance vanishes and from which magnetic flux fields are expelled. Good conductors weak scattering from the lattice are poor superconductors low tc. The phenomenon of superconductivity, in which the electrical resistance of certain. Ferro magnetic and anti ferromagnetic materials are not. Is it correct to talk about the vanishingof the electrical resistance. If the superconductor were simply a perfect conductor with in. What is a superconductor, discovery of superconductivity, meissner effect, type i superconductors, type ii superconductors, theory of superconductivity, tunneling and the josephson effect, hightemperature supercondutors and applications of superconductors. Foundations of bcs theory in this section, we lay out the theoretical grounds for bcs theory. A microscopic theory of superconductivity was developed in 1957 by john bardeen, leon cooper and j. Lecture 23 superconductivity ii theory 4 physics 460 f 2000 lect 23 19 persistent currents how can the current stop flowing.
Applied superconductivity lecture notes pdf 35p download book. Superconductivity basic phenomenon if a material is described as a superconductor, below a certain temperature the critical temperarure it loses its electrical resistivity to become a perfect conductor. Superconductivity and bcs theory introduction electronphonon interaction, cooper pairs bcs wave function, energy gap and quasiparticle states predictions of the bcs theory limits of the bcs gap equation. Discovery superconductivity was discovered in 1911 by the dutch physicist heike kamerlingh onnes. The more impure the metal electrical resistivity certain. Pdf superconductivity and their applications researchgate. Superconductivity of metals and alloyswestview press, 1999. Note also that in the superconductor ndfeaso1x, an example of the recent. Superconductivity is the set of physical properties observed in certain materials, wherein. Mod01 lec27 superconductivity perfect electrical conductivity and perfect diamagnetism duration. Provides an explanation of the superconductivity of type i superconductors. Superconductors are used in the following applications. Bcs theory or bardeencooperschrieffer theory named after john bardeen, leon cooper, and john robert schrieffer is the first microscopic theory of superconductivity since heike kamerlingh onness 1911 discovery.
It is no surprise that all major uses for superconductors rely on two major properties. Mri scanners, which contain liquid helium refrigeration. It was first discovered by the dutch physicist heike kamerlingh. Department of physics of the university of florence, via g. Background history kammerlingh onnes liquefying of he in 1908. The phenomenon was discovered in 1911 by heike kamerlingh onnes kamerlingh onnes, heike, 18531.
Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even. Figure 17 superconducting machines offer advantages in size and. Hightemperature superconductivity the nobel prize in physics 1987 for their important breakthrough in the discovery of superconductivity in ceramic materials j. The bcs theory explains the super conductivity of only type i superconductors and does not explain type ii superconductors. Eremin, maxplanck institut fur physik komplexer systeme, dresden, germany. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Lecture notes on superconductivity a work in progress daniel arovas congjun wu department of physics university of california, san diego june 23, 2019. Mechanism of superconductivity isotope effect, tc depends on the mass of atoms t c mass of atoms constitutingthe crystallattice. By focusing our attention on them we were able to construct a theory of superconductivity. As a result, persistent current comes into existence so that h m and all the magnetic flux lines are repelled by the superconductor as. The aim of bcs theory is to provide a satisfactory explanation to the superconductivity of type i superconductors. There is an energy barrier for the flux to go through the superconductor to escape time for. Tinkham, introduction to superconductivity 2nd editiondover, 2004.
Of superconductivity, the advantages of superconducting metamaterials over their. Center for nanophysics and advanced materials, physics department. Disorder version of the abelian higgs model and the order of the superconductive phase transition pdf. The main advantages of devices made from superconductors are low power dissipation, highspeed operation, and high sensitivity. K electrical resistivity is 0 for perfectly pure metal any metal cant be perfectly pure. Superconductivity is observed in a large variety of materials but, remarkably, not in some of the best normal conductors like copper, silver and gold, except at very high pressures. Tech sem i engineering physics uiii chapter 2superconductivity 1. Jun 11, 2012 a description of superconductivity in a little more detail than you need at a level to explain the basic concepts of a quantum mechnical phenomenon. Any material exhibiting these properties is a superconductor. The electric power grid is among the greatest engineering achievements of the 20th century. Condensed matter and qcd lectures at the university of barcelona, spain, septemberoctober 2003 roberto casalbuoni. However, these are just the notes of a oneterm twohours lecture to introduce into the spirit of this kind of theoretical approach, not only addressing theorists. Superconductivity superconductivity was discovered in 1911 by h.
Applied superconductivity lecture notes pdf 35p this note covers the following topics. Kamerlingh onnes in holland while studying the electrical resistance of a sample of frozen mercury as a function of temperature. This fact was used to advantage during the commissioning of the hera proton. Pdf lecture note on superconductivity, solid state physics. Free superconductivity books download ebooks online textbooks. All derivations may be referenced in \theory of superconductivity by bardeen, cooper, and schrie er or tinkhams introduction to superconductivity. Superconductivity a level physics teaching resources. Superconductivity is characterized by three hallmark properties, these being zero dc resistance, a fully diamagnetic meissner effect, and macroscopic quantum phenomena. Explains the relative difference in superconductivity between metals, better conductors at normal temperatures are terrible superconductors. Certain materials called superconductors by definition have zero resistivity or infinite conductivity.
Soon after its discovery in 1911 by dutch physicist heike kamerlingh onnes and his collaborators, cornelis dorsman, gerrit jan flim and gilles holst, superconductivity inspired dreams of noloss electrical transmission. For chemically pure and structurally perfect specimen, the superconductivity is very sharp. On cooling hg to the temperature of liquid helium, he found that the resistance vanished abruptly at. Find materials for this course in the pages linked along the left. Aug 09, 2011 this summer, in partnership with the initiative for sustainability and energy at northwestern isen, science in society will profile four innovators in the areas of energy and sustainability researchers who are harnessing the power of science and engineering to better understand and even solve some of the many challenges facing our planet. Explains superconductivity within the realms of classical mechanics. It is important to note that this equation is not valid in a normal conductor. Magnetic resonance imaging, or mri, uses powerful superconducting. The physics and applications of superconducting metamaterials. One of the first largescale applications of superconductivity is in medical diagnosis. Alexander muller 12 of the prize 12 of the prize federal republic of germany switzerland ibm zurich research laboratory ruschlikon, switzerland ibm zurich research. Superconductivity was discovered by kamerlinghonnes in 1911, when he was studying the transport properties of hg mercury at low temperatures. Magnetic resonance imaging, or mri, uses powerful superconducting magnets to produce large and uniform magnetic fields inside the patients body. Superconductivity is widely regarded as one of the great scientific discoveries of the 20th century.
Lecture notes applied superconductivity electrical. Fernandes here we will discuss a new ground state of the interacting electron gas. Nearly a century after its first discovery, its full commercial potential is. Robert schrieffer, which is known as the bcs theory. Note what everyone does in order to get the magnet to levitate stably. Materials having high normal resistivities exhibit superconductivity. Superconductors and related technologies will translate into significant benefits to our life, our societies and economies across a broad range of endeavors.
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