minigap
A minigap is a small energy gap that can appear in the electronic spectrum of mesoscopic systems. It typically occurs in a region that is proximitized by a superconductor or limited by finite size, and is smaller than the intrinsic gap of the parent material. The minigap signals a suppression of low-energy states near the Fermi level.
In superconducting hybrids such as SNS (superconductor–normal–superconductor) or NSN structures, a minigap opens in the local
Its magnitude depends on geometry and transport regime. In diffusive SNS junctions the minigap scales with
Experimentally, minigaps have been observed in semiconductor–superconductor hybrids (for example InAs or InSb nanowires, graphene, and
The term is distinct from the bulk gap Δ of the superconductors involved. The minigap is often described