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In research published recently in the scientific
journal Nature, Los Alamos scientists Tuson Park, Joe D. Thompson, and
their colleagues describe the discovery of hidden magnetism in the
CeRhIn5 compound. In studying the compound, researchers found that a
purely unconventional superconducting phase is separated from a phase
of coexisting magnetism and unconventional superconductivity, with the
boundary between these two phases controlled by the laws of quantum
physics.
Unconventional superconductors are materials that
exhibit superconductivity, a complete absence of electrical resistance
under cold temperatures, but use exotic mechanisms. Conventional
wisdom has long held that the magnetism is excluded as materials
change phases, but the researchers now show that it is merely hidden
by unconventional superconductivity and can be made to reappear in the
presence of an applied magnetic field.
According to Thompson, "this discovery provides an
exciting opportunity to better understand how magnetism and
unconventional superconductivity are related in more-complex materials
and may reveal more about the technologically important field of high
temperature superconductors."
At low temperatures, electrons in a metal can pair
with each other to create superconductivity, align in a magnetically
ordered state, or do neither. Until recently, these mutually exclusive
options for electrons were the norm, but the discovery of complex
electronic materials like CeRhIn5, which can sustain more exotic forms
of superconductivity, now shows that electrons can participate
simultaneously in magnetism and superconductivity. |
