A superconducting magnet is an electromagnet made from coils of superconducting wire. They must be cooled to cryogenic temperatures during operation In its superconducting state, the wire has no electrical resistance and can therefore conduct electrical currents much larger than ordinary wire, creating intense magnetic fields. Superconducting magnets can produce stronger magnetic fields than all non-superconducting electromagnets, and large superconducting magnets can be cheaper to operate because no energy is dissipated as heat in the windings. They are used in MRI instruments in hospitals and scientific equipment such as nuclear magnetic resonance spectrometers, mass spectrometers, fusion reactors, and particle accelerators. They are also used for levitation, guidance, and propulsion on a magnetic levitation (maglev) railway system being built in Japan.

In 2017, a YBCO magnet created by the National High Magnetic Field Laboratory (NHMFL) broke the previous world record with a strength of 32 T. This is an all-superconducting user magnet, designed to last for many decades. They hold the current record as of March 2018. In 2019, a new world record of 32.35 T with an all-superconducting magnet was achieved by the Institute of Electrical Engineering, Chinese Academy of Sciences (IEE, CAS). No-insulation technique for the HTS insert magnet is also used. In 2019, the NHMFL also developed a non-insulated YBCO test coil combined with a resistive magnet and broke the lab's own world record for the highest continuous magnetic field for any configuration of the magnet at 45.5 T. At 1.2 GHz (28.2 T) NMR magnet was achieved in 2020 using an HTS magnet. In 2022, the Hefei Institutes of Physical Science, Chinese Academy of Sciences (HFIPS, CAS) claimed the new world record for the strongest steady magnetic field of 45.22 T reached, while the previous NHMFL 45.5 T record in 2019 was reached when the magnet failed immediately in a quench.

Physicists explore the concept that cold states of matter can form repeated patterns in time. The phrases "perpetual-motion machine"—a concept derided by scientists since the mid-19th century—and "physics Nobel laureate Frank Wilczek" wouldn't seem to belong in the same sentence. But if Wilczek's latest ideas on symmetry and the nature of time are correct, they would suggest the existence of a bona fide perpetual motion machine— albeit one from which energy could never be extracted. He proposes that matter could form a "time crystal," whose structure would repeat periodically, as with an ordinary crystal, but in time rather than in space. Such a crystal would represent a previously unknown state of matter and might have arisen as the very early universe cooled, losing its primordial symmetries.