What is a superconductor? - Livescience.com

A superconductor is a material that achieves superconductivity, which is a state of matter that has no electrical resistance and does not allow magnetic fields to penetrate.

In 1911, Onnes was studying the electrical properties of mercury in his laboratory at Leiden University in The Netherlands when he found that the electrical resistance in the mercury completely vanished when he dropped the temperature to below 4.2 Kelvin — that's just 4.2 degrees Celsius (7.56 degrees Fahrenheit) above absolute zero.

He found that the electric current persisted in the mercury without decreasing, confirming the lack of electrical resistance and opening the door to future applications of superconductivity.

In 1933, physicists Walther Meissner and Robert Ochsenfeld discovered that superconductors "expel" any nearby magnetic fields, meaning weak magnetic fields can't penetrate far inside a superconductor, according to Hyper Physics, an educational site from the Georgia State University department of physics and astronomy.

It wasn't until 1950 that theoretical physicists Lev Landau and Vitaly Ginzburg published a theory of how superconductors work, according to Ginzburg's biography on The Nobel Prize website.

To create electrical resistance, the electrons in a metal need to be free to bounce around.

These electron pairs, called Cooper pairs, are very stable at low temperatures, and with no electrons "free" to bounce around, the electrical resistance disappears.

Locked up like this, the electrons can't provide any electrical resistance, and electricity can flow through the metal perfectly, according to the University of Cambridge.

However, because superconductors have no electrical resistance, no heat is generated, and the electromagnets can generate the necessary magnetic fields.

Because of the unique properties of electrical currents in superconductors, they can be used to construct quantum computers.

The next challenge is to develop a theory that explains how the novel superconductors work and predict the properties of those materials, Dogan told Live Science in an email. .

LTS can be described by the BCS theory to explain how the electrons form Cooper pairs, while HTS use other microscopic methods to achieve zero resistance.

Room-temperature superconductors would allow for the electrical transmission of energy with no losses or waste, more efficient maglev trains, and cheaper and more ubiquitous use of MRI technology.

The practical applications of room-temperature superconductors are limitless — physicists just need to figure out how superconductors work at room temperatures and what the "Goldilocks" material to allow for superconductivity might be.