The capacity to produce the superconducting, magnetic and photonic materials that underpin high-field magnets, quantum and fusion machines, power systems and photonics.
The Capability Development Index tracks the events that move a capability — operational use, technical breakthroughs, procurement decisions and the industrial base behind them — and places each on the record with the date it happened.
Recent developments cover the current period. Historical developments are the inflection points that produced Superconducting, Magnetic & Photonic Materials as it stands today.
The Greek philosopher's discussion is among the earliest surviving Western accounts of magnetism, with the term magnet later derived from Magnesia, the region where the ore was found.
Early Chinese philosophical and technical texts describe lodestone's ability to attract iron, predating similar observations recorded in the Mediterranean world by several centuries.
The Song dynasty scholar described a magnetised needle compass used for navigation, along with an early account of magnetic declination, in his Dream Pool Essays.
Sturgeon wound insulated wire around an iron core to create a magnet capable of lifting many times its own weight, moving magnetism from a natural curiosity to an engineerable technology.
Working at Leiden and studying the resistance of mercury at cryogenic temperatures using newly produced liquid helium as a refrigerant, Onnes observed that electrical resistance vanished abruptly at 4.2 K. The precise date and circumstances were only reconstructed a century later when his notebook was found. He received the 1913 Nobel Prize in Physics for his low-temperature work, including the production of liquid helium.
Following the mercury result, superconductivity was identified in further elemental metals, showing the phenomenon was general rather than peculiar to mercury. This widened the search for practical superconducting materials.
The German physicists found that superconductors actively expel magnetic fields from their interior, a defining property distinct from merely having zero electrical resistance and essential to later levitation applications.
The brothers showed that the Meissner effect follows from minimising the electromagnetic free energy carried by the superconducting current. Their classical phenomenological model gave the first quantitative account of how magnetic field decays with depth inside a superconductor, defining the London penetration depth.
Niobium nitride raised the known critical temperature substantially above that of the elemental superconductors. It marked the beginning of niobium-based compounds as the most promising family for practical superconducting technology.
Combining Landau's theory of second-order phase transitions with a Schrödinger-like wave equation, the theory successfully explained the macroscopic properties of superconductors. Abrikosov later used it to predict the division into Type I and Type II superconductors, the latter underpinning all high-field magnet technology. Abrikosov and Ginzburg shared the 2003 Nobel Prize for this work.
The isotope effect showed that the transition temperature varied with the mass of the constituent element's isotopes. This pointed directly to the electron–phonon interaction as the microscopic mechanism of superconductivity, guiding theorists towards BCS theory.
The cryotron combined two superconductors with very different critical magnetic fields to make a fast, simple switch for computer elements. It was the first practical application of superconductivity, and in the 1950s and 1960s cryotron switches were used to build experimental digital computers.
Onnes had attempted superconducting electromagnet windings soon after 1911 but found modest fields destroyed superconductivity in the materials available. Yntema's small iron-core magnet with niobium wire windings was the first success, opening the path to superconducting magnet engineering.
BCS theory explained the superconducting current as a superfluid of Cooper pairs — electron pairs bound through the exchange of phonons. It provided the complete microscopic account of conventional superconductivity and earned its authors the 1972 Nobel Prize.
Bogolyubov showed in 1958 that the variationally derived BCS wavefunction could be obtained by a canonical transformation of the electronic Hamiltonian. In 1959 Gor'kov demonstrated that BCS theory reduces to Ginzburg–Landau theory near the critical temperature, unifying the microscopic and phenomenological pictures.
At 4.2 K the compound carried over 100,000 amperes per square centimetre in an 8.8-tesla field. Though brittle and hard to fabricate, niobium–tin proved capable of generating fields as high as 20 tesla, making high-field superconducting magnets feasible.
Commercial production of niobium–titanium supermagnet wire commenced immediately at Westinghouse Electric Corporation and Wah Chang Corporation. Despite weaker superconducting properties than niobium–tin, its ductility and ease of fabrication made it the workhorse magnet material for MRI scanners and particle accelerator magnets.
Josephson predicted theoretically that a supercurrent can flow between two superconductors separated by a thin insulating layer. The effect underpins SQUID magnetometers and the most accurate measurements of the magnetic flux quantum, and hence of the Planck constant. He received the Nobel Prize in 1973.
Using a theory in which vortex lines play the major role, it was shown that the transition is second order in the Type II regime and first order in the Type I regime, separated by a tricritical point. This refined earlier 1970s calculations suggesting a weakly first-order transition due to long-range electromagnetic fluctuations.
Researchers in the United States and Japan developed the strongest permanent magnets yet made, now standard in electric motors, wind turbines and hard disk drives.
Additional categories of processed rare earth elements and finished neodymium magnets were brought under export licensing, tightening a supply-chain lever China had used with increasing frequency amid trade tensions with the United States and its partners.
Japanese trading houses and manufacturers expanded financial backing for rare earth processing capacity in Australia and elsewhere, continuing a decade-long effort to reduce dependence on Chinese-processed magnet materials.
Funding under the government programme aimed to establish domestic processing and neodymium-iron-boron magnet production, reducing near-total reliance on imported magnets for electric motors and defence systems.
The superconducting tokamak extended the length of time it could sustain high-temperature, high-confinement plasma, building on a series of incremental records that support the design of future fusion reactors.
Assembly of the Massachusetts-based fusion company's high-temperature superconducting magnet tokamak advanced toward a planned first-plasma milestone, continuing to attract private investment on the strength of its compact magnet design.
The Australian company increased processing capacity at its Malaysian and domestic facilities, adding to the small number of rare earth separation plants operating outside China.
The prototype, tested on a dedicated track, targeted commercial speeds well above those of conventional high-speed rail, extending China's decade-long programme of superconducting and electromagnetic maglev development.
The British fusion company advanced testing of its magnet technology, part of a wave of privately funded fusion ventures betting that high-temperature superconducting magnets can make reactors smaller and cheaper than earlier designs.
Continued technical issues with reactor components, including magnet system integration, pushed back the target date for first plasma at the fusion research project, jointly funded by partners including the EU, China, India and the United States.
The facility sustained high-confinement plasma for over 1,000 seconds, a new record for steady-state operation and a significant data point for the physics underpinning future fusion power plants.
A twisted three-layer graphene device was shown to superconduct at about 2.8 K in 2021, followed by an untwisted trilayer device at 1–2 K in 2022. The untwisted device proved tunable, allowing rapid testing of an unprecedented number of configurations for superconductivity, with applications in quantum computing.
The first development and study of a superconducting BEC suggested a smooth transition between the BEC and Bardeen-Cooper-Schrieffer regimes. It linked ultracold atomic physics with conventional superconducting pairing theory.
A bilayer graphene sheet twisted by 1.1 degrees superconducted at about 1.7 K, the first success with two-dimensional materials. The moiré superlattice slows electrons enough for their collective interactions to drive Cooper pairing, creating a highly tunable platform for studying superconductivity.
Hydrogen sulphide was found to superconduct at 203 K, the highest critical temperature recorded for a conventional superconductor. The result required pressures of approximately 90 gigapascals, limiting practical use but reframing the search for room-temperature superconductivity.
The trainset, levitated and propelled by superconducting magnets, reached 603 kilometres per hour on the Yamanashi test track, the fastest speed ever recorded by a passenger rail vehicle.
The consortium estimated that global economic activity for which superconductivity was indispensable amounted to about five billion euros. MRI systems accounted for roughly 80 per cent of that total, showing medical imaging as the dominant commercial market for superconducting magnets.
It was suggested that the same mechanism producing superconductivity could yield materials with almost infinite electrical resistance. The proposal extended the theoretical reach of pairing physics beyond zero-resistance behaviour.
Currents injected into superconducting coils persisted from August 1995 until March 2024 without a power source. The demonstration provided a practical measure of the effectively infinite lifetime of supercurrents, experimentally bounded at over 100,000 years.
Replacing lanthanum with yttrium in the cuprate structure lifted the transition temperature to 92 K, above the 77 K boiling point of liquid nitrogen. Cheap liquid nitrogen cooling made a wide range of superconducting experiments and applications practical for the first time.
Working at IBM's Zurich laboratory, Bednorz and Müller found that certain cuprate-perovskite ceramics superconduct above 35 K, a transition temperature theoretically impossible for a conventional superconductor. The materials were termed high-temperature superconductors, opening an entirely new class of materials and earning the pair the 1987 Nobel Prize in Physics.