A wire made of superconducting material that conducts electricity without resistance when cooled below a critical temperature.A superconducting wire is a conductor made from a material that, when cooled below its critical temperature, loses all electrical resistance. This allows electric current to flow indefinitely without energy loss, a stark contrast to ordinary wires that dissipate energy as heat. Superconducting wires are fundamental to building powerful electromagnets, such as those in MRI machines and particle accelerators, and are also key components in quantum computing, where they form the basis of qubits and interconnects.
Superconductivity was discovered by Heike Kamerlingh Onnes in 1911, who observed zero resistance in mercury at 4.2 K. The theoretical explanation came in 1957 with the BCS theory by Bardeen, Cooper, and Schrieffer.
In a superconductor, electrons form Cooper pairs—bound pairs that condense into a single quantum state described by a macroscopic wavefunction. This state is resistant to scattering by impurities or lattice vibrations, so the pairs move coherently without resistance. The critical temperature depends on the material and can be raised by pressure or strain, as seen in some thin films. In quantum circuits, superconducting wires carry current without dissipation, preserving fragile quantum states.
Superconducting wires are used in MRI magnets, particle accelerators like the LHC, and in quantum processors where they connect qubits and form resonant circuits.
A superconducting wire can carry a persistent current for years without any power source, as demonstrated in experiments where currents have lasted for over a decade.


















