Broken time-reversal symmetry in iron-based superconductors

Magnetic fields inside a superconductor with broken time-reversal symmetry: Red and blue arrows illustrate the direction and strength of the internal magnetic fields for forward and backward time development. Credit: Hans-Henning Klauss

Physicists at TU Dresden have discovered spontaneous static magnetic fields with broken time-reversal symmetry in a class of iron-based superconductors. This exceptional property calls for new theoretical models and may become important in quantum computing.

Forwards or backwards makes no difference, scientists call this a time-reversal symmetry.

For decades this symmetry was also found in all superconductors. Superconductors are materials which can conduct electrical currents at low temperatures without energy dissipation. One of their major applications is the efficient generation of strong magnetic fields, for example in magnetic resonance imaging (MRI) diagnosis. Approximately 99% of all known superconducting materials are time-reversal symmetric.

The synthesis of this versatile class of intermetallic compounds is comparatively simple. Therefore, these iron-based superconductors have an enormous potential for applications. (Phys.org)

The research results have been published in the scientific journal Nature Physics.