In
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...
, reentrant superconductivity is an effect observed in systems that lie close to the boundary between
ferromagnetic
Ferromagnetism is a property of certain materials (such as iron) which results in a large observed magnetic permeability, and in many cases a large magnetic coercivity allowing the material to form a permanent magnet. Ferromagnetic materials ...
and
superconducting
Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...
. By its very nature (normal) superconductivity (condensation of electrons into the
BCS
BCS, or bcs, may refer to:
American football
* Bowl Championship Series, a system that selected matchups for major college football bowl games between 1998 and 2013
* BCS conferences, the six FBS conferences with automatic major bowl bids under ...
ground state) cannot exist together with ferromagnetism (condensation of electrons into the same
spin
Spin or spinning most often refers to:
* Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning
* Spin, the rotation of an object around a central axis
* Spin (propaganda), an intentionally b ...
state, all pointing in the same direction). Reentrance is when while changing a continuous parameter, superconductivity is first observed, then destroyed by the ferromagnetic order, and later reappears.
An example is the changing of the thickness of the ferromagnetic layer in a bilayer of a superconductor and a ferromagnet. At a certain thickness superconductivity is destroyed by the
Andreev reflected electrons in the ferromagnet, but if the thickness increases, this effect disappears again.
Another example are materials with a
Curie temperature
In physics and materials science, the Curie temperature (''T''C), or Curie point, is the temperature above which certain materials lose their permanent magnetic properties, which can (in most cases) be replaced by induced magnetism. The Cu ...
below the superconducting transition temperature. When cooling, first superconducting order appears in the electron system. Cooling further, the ferromagnetic order energetically wins over the superconducting order in the electron system. At even lower energy superconductivity reenters, and a nonuniform magnetic order appears. there is ferromagnetic order on short length scales, but superconducting order on large length scales.
Examples
Uranium ditelluride
Uranium ditelluride is an inorganic compound with the formula UTe2. It was discovered to be an unconventional superconductor in 2018.
*
Superconductivity
Superconductivity in UTe2 appears to be a consequence of triplet electrons spin-pairing. ...
, (UTe
2) a spin-triplet superconductor. Discovered to be a superconductor in 2018.
''Unconventional superconductor acts the part of a promising quantum computing platform'' 2021
/ref>
See also
* Ferromagnetic superconductor
Further reading
''Ferromagnetism and reentrant superconductivity'' 1998
''Reentrant Superconductivity of CeRu2'' 1993
''Reentrant superconductivity in Eu(Fe1−xIrx)2As2'' 2013
References
{{Superconductivity
Superconductivity