n the field of superconductivity—the phenomenon in which electrons can flow through a material with essentially zero resistance—the "holy grail" of discovery is a superconductor that can perform under everyday temperatures and pressures. Such a material could revolutionize modern life. But currently, even the "high-temperature" (high-Tc) superconductors that have been discovered must be kept very cold to function—too cold for most applications.
Scientists still have much to learn before room-temperature superconductivity can be realized, largely because superconductors are highly complex materials with interwoven and sometimes competing magnetic and electronic states. These different states, or phases, can be very difficult to untangle and interpret.
One such state is an alternate superconducting state of matter known as a pair density wave (PDW), which is characterized by coupled pairs of electrons that are constantly in motion. PDWs have been thought to only arise when a superconductor is placed within a large magnetic field—until now, that is.
Recently, researchers from the U.S. Department of Energy's Brookhaven National Laboratory, Columbia University, and Japan's National Institute of Advanced Industrial Science and Technology directly observed a PDW in an iron-based superconducting material with no magnetic field present. They describe their results in the June 28, 2023, online edition of the journal Nature.
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