Proximityinduced

Proximity-induced, often described via the proximity effect, refers to the appearance of properties in a material that arise because the material is in contact with another material that possesses those properties. The phenomenon is most commonly discussed in superconductivity, magnetism, and other ordered states that can extend across an interface.

In a superconducting proximity effect, a normal metal or semiconductor placed adjacent to a superconductor inherits superconducting correlations. Cooper pair wavefunctions leak into the non-superconducting region through the interface, producing an induced gap and a finite pair amplitude that decay over a characteristic length known as the coherence length. The strength and decay depend on interface transparency, temperature, and material quality.

Magnetic proximity effect occurs when a nonmagnetic material near a ferromagnet exhibits induced magnetization or exchange splitting. This induced moment is typically confined to a few atomic layers and influences spin transport, anisotropies, and damping in devices such as spin valves and magnetic tunnel junctions.

Proximity-induced superconductivity is also studied in topological insulators and semiconductors with strong spin-orbit coupling, where superconducting pairing is induced in surface or interface states. Such systems are of interest for realizing Majorana bound states in hybrid superconducting devices.

Realizing and exploiting proximity-induced effects relies on high-quality interfaces and careful control of thickness, disorder, and temperature. They enable hybrid devices that combine distinct electronic orders, with applications in quantum information processing, superconducting electronics, and spintronics.