Ultra-thin designer materials unlock quantum phenomena

A team of theoretical and experimental physicists have designed a new ultra-thin material that they have used to create elusive quantum states. Called one-dimensional Majorana zero energy modes, these quantum states could ...

Acoustic plasmons found in hole-doped cuprate superconductors

The presence of acoustic plasmons in p-type (hole-doped) cuprate superconductors has now been confirmed by Dr. Ke-Jin Zhou and his team using high-resolution RIXS (Resonant Inelastic X-ray Scattering), at Diamond Light Source's ...

Researchers establish proof of principle in superconductor study

Three physicists in the Department of Physics and Astronomy at the University of Tennessee, Knoxville, together with their colleagues from the Southern University of Science and Technology and Sun Yat-sen University in China, ...

Connecting two classes of unconventional superconductors

The understanding of unconventional superconductivity is one of the most challenging and fascinating tasks of solid-state physics. Different classes of unconventional superconductors share that superconductivity emerges near ...

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Superconductivity

Superconductivity is a phenomenon occurring in certain materials generally at very low temperatures, characterized by exactly zero electrical resistance and the exclusion of the interior magnetic field (the Meissner effect). It was discovered by Heike Kamerlingh Onnes in 1911. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It cannot be understood simply as the idealization of "perfect conductivity" in classical physics.

The electrical resistivity of a metallic conductor decreases gradually as the temperature is lowered. However, in ordinary conductors such as copper and silver, impurities and other defects impose a lower limit. Even near absolute zero a real sample of copper shows a non-zero resistance. The resistance of a superconductor, despite these imperfections, drops abruptly to zero when the material is cooled below its "critical temperature". An electric current flowing in a loop of superconducting wire can persist indefinitely with no power source.

Superconductivity occurs in a wide variety of materials, including simple elements like tin and aluminium, various metallic alloys and some heavily-doped semiconductors. Superconductivity does not occur in noble metals like gold and silver, nor in pure samples of ferromagnetic metals.

In 1986 the discovery of a family of cuprate-perovskite ceramic materials known as high-temperature superconductors, with critical temperatures in excess of 90 kelvin, spurred renewed interest and research in superconductivity for several reasons. As a topic of pure research, these materials represented a new phenomenon not explained by the current theory. In addition, because the superconducting state persists up to more manageable temperatures, past the economically-important boiling point of liquid nitrogen (77 kelvin), more commercial applications are feasible, especially if materials with even higher critical temperatures could be discovered.

See also the history of superconductivity.

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