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Superconductivity | Physics, Properties, & Applications | Britannica Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos superconductivity Introduction Discovery Thermal properties of superconductors Transition temperatures Specific heat and thermal conductivity Energy gaps Magnetic and electromagnetic properties of superconductors Critical field The Meissner effect High-frequency electromagnetic properties Magnetic-flux quantization Josephson currents Higher-temperature superconductivity Discovery and composition of high-temperature superconductors Structures and properties Applications References & Edit History Quick Facts & Related Topics Images At a Glance superconductivity summary Quizzes Electricity: Short Circuits & Direct Currents Related Questions What does pH stand for? What is considered neutral on the pH scale? How is pH measured? What is the pH scale used for? Is mathematics a physical science? print Print Please select which sections you would like to print: Table Of Contents CITE verified Cite While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. Select Citation Style MLA APA Chicago Manual of Style Copy Citation Share Share Share to social media Facebook X URL https://www.britannica.com/science/superconductivity Feedback External Websites Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article. External Websites American Institute of Physics - Moments of Discovery - Superconductivity: So simple, yet so hard to explain! Live Science - What is a superconductor? Engineering LibreTexts - Superconductivity Energy.gov - Superconductivity Boston University Arts and Sciences - Physics - Superconductivity Magnet Academy - Superconductivity University of Bristol - School of Physics - Superconductivity University of Central Florida Pressbooks - University Physics Volume 2 - Superconductors Nature - Nature Communications - Mechanism of superconductivity and electron-hole doping asymmetry in κ-type molecular conductors Clark Digital Commons - Superconductivity and Fermi Surface Studiesof β″-(BEDTTTF)2[(H2O)(NH4)2Cr(C2O4)3]·18-Crown-6 (PDF) OpenStax - University Physics Volume 3 - Superconductivity superconductivity physics Ask Anything Quick Summary Homework Help Also known as: cryogenic conductor, superconductor Written by Donald M. Ginsberg Professor Emeritus of Physics, University of Illinois at Urbana-Champaign. Editor of Physical Properties of High Temperature Superconductors. Donald M. Ginsberg Fact-checked by Britannica Editors Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Britannica Editors Last updated May 5, 2026 • History Britannica AI Ask Anything Quick Summary Table of Contents Table of Contents Quick Summary Ask Anything Top Questions What is superconductivity? How does a material behave when it becomes a superconductor? At what conditions do materials become superconductors? What is the Meissner effect in superconductivity? How is superconductivity useful in real-life technology? What are some current challenges in using superconductors more widely? Show more Show less News • Scientists just captured a mysterious quantum “dance” inside superconductors • Apr. 27, 2026, 11:06 AM ET (ScienceDaily) Show less superconductivity , complete disappearance of electrical resistance in various solids when they are cooled below a characteristic temperature. This temperature, called the transition temperature , varies for different materials but generally is below 20 K (−253 °C). The use of superconductors in magnets is limited by the fact that strong magnetic fields above a certain critical value, depending upon the material, cause a superconductor to revert to its normal, or nonsuperconducting, state, even though the material is kept well below the transition temperature. Suggested uses for superconducting materials include medical magnetic-imaging devices, magnetic energy-storage systems, motors, generators, transformers, computer parts, and very sensitive devices for measuring magnetic fields, voltages, or currents. The main advantages of devices made from superconductors are low power dissipation , high-speed operation, and high sensitivity. Discovery Superconductivity was discovered in 1911 by the Dutch physicist Heike Kamerlingh Onnes ; he was awarded the Nobel Prize for Physics in 1913 for his low-temperature research. Kamerlingh Onnes found that the electrical resistivity of a mercury wire disappears suddenly when it is cooled below a temperature of about 4 K (−269 °C); absolute zero is 0 K, the temperature at which all matter loses its disorder. He soon discovered that a superconducting material can be returned to the normal (i.e., nonsuperconducting) state either by passing a sufficiently large current through it or by applying a sufficiently strong magnetic field to it. For many years it was believed that, except for the fact that they had no electrical resistance (i.e., that they had infinite electrical conductivity), superconductors had the same properties as normal materials. This belief was shattered in 1933 by the discovery that a superconductor is highly diamagnetic ; that is, it is strongly repelled by and tends to expel a magnetic field. This phenomenon, which is very strong in superconductors, is called the Meissner effect for one of the two men who discovered it. Its discovery made it possible to formulate, in 1934, a theory of the electromagnetic properties of superconductors that predicted the existence of an electromagnetic penetration depth, which was first confirmed experimentally in 1939. In 1950 it was clearly shown for the first time that a theory of superconductivity must take into account the fact that free electrons in a crystal are influenced by the vibrations of atoms that define the crystal structure , called the lattice vibrations. In 1953, in an analysis of the thermal conductivity of superconductors, it was recognized that the distribution of energies of the free electrons in a superconductor is not uniform but has a separation called the energy gap . Britannica Quiz Electricity: Short Circuits & Direct Currents The theories referred to thus far served to show some of the interrelationships between observed phenomena but did not explain them as consequences of the fundamental laws of physics . For almost 50 years after Kamerlingh Onnes’s discovery, theorists were unable to develop a fundamental theory of superconductivity. Finally, in 1957 such a theory was presented by the physicists John Bardeen , Leon N. Cooper , and John Robert Schrieffer of the United States; it won for them the Nobel Prize for Physics in 1972. It is now called the BCS theory in their honour, and most later theoretical work is based on it. The BCS theory also provided a foundation for an earlier model that had been introduced by the Russian physicists Lev Davidovich Landau and Vitaly Lazarevich Ginzburg (1950). This model has been useful in understanding electromagnetic properties, including the fact that any internal magnetic flux in superconductors exists only in discrete amounts (instead of in a continuous spectrum of values), an effect called the quantization of magnetic flux . This flux quantization, which had been predicted from quantum mechanical principles, was first observed experimentally in 1961. In 1962 the British physicist Brian D. Josephson predicted that two superconducting objects placed in electric contact would display certain remarkable electromagnetic properties. These properties have since been observed in a wide variety of experiments, demonstrating quantum mechanical effects on a macroscopic scale. Explore Britannica Premium! Trusted knowledge for those who want to know more. SUBSCRIBE The theory of superconductivity has been tested in a wide range of experiments, involving, for example, ultrasonic absorption studies, nuclear-spin phenomena, low-frequency infrared absorption, and electron-tunneling experiments. The results of these measurements have brought understanding to many of the detailed properties of various superconductors. Thermal properties of superconductors Superconductivity is a startling departure from the properties of normal (i.e., nonsuperconducting) conductors of electricity. In materials that are electric conductors, some of the electrons are not bound to individual atoms but are free to move through the material; their motion constitutes an electric current . In normal conductors these so-called conduction electrons are scattered by impurities, dislocations, grain boundaries, and lattice vibrations (phonons). In a superconductor, however, there is an ordering among the conduction electrons that prevents this scattering. Consequently, electric current can flow with no resistance at all. The ordering of the electrons, called Cooper pairing, involves the momenta of the electrons rather than their positions. The energy per electron that is associated with this ordering is extremely small, typically about one thousandth of the amount by which the energy per electron changes when a chemical reaction takes place. One reason that superconductivity remained unexplained for so long is the smallness of the energy changes that accompany the transition between normal and superconducting states. In fact, many incorrect theories of superconductivity