Superconductivity and Local Inversion-Symmetry Breaking

Inversion and time reversal are essential symmetries for the structure of Cooper pairs in superconductors. The loss one or both leads to modifications this can change properties superconducting phases profound ways. Lacking inversion, superconductivity noncentrosymmetric materials has become an important topic, particular, context topological as well unusual magnetic magneto-electric properties. Recently, crystal structures with local, but not global inversion-symmetry breaking have attracted attention, exhibit phenomena naively expected centrosymmetric materials. After introducing concept locally crystals different material realizations, we discuss consequences such local symmetry on classification, and, parts, already observed phenomenology unconventional superconductivity, possible phases.