Intrinsic Topological Superconductivity in Iron-based High-Temperature Superconductors

Looking for Majorana fermions and realizing quantum computing have been the forefront of condensed matter physics in recent years. Topological superconductivity plays a key role to this end. However, topological superconductivity is believed to be a rare phenomenon whose realization requires strict conditions. Previous proposals invoke p-wave superconductor such as Sr₂RuO₄, or proximity effect induced by putting topological insulators on top of a superconductor. Another route is to find intrinsic topological superconductors whose presence is still very limited. Here we show that intrinsic topological superconductivity can be realized in a number of iron-based high-temperature superconductors. Using first-principles many-body-theory calculations, we find that several iron-based superconductors are non-topological according to band theory but become topological when the strong electronic correlation effects are properly taken into account. Our results provide a new route to achieve and tune topological superconductivity and shed new lights on realizing topological quantum computing.