Enhanced superconductivity in monolayer FeSe films on SrTiO₃(001) via metallic δ-doping

Interface engineering has been proven to be effective in discovering new quantum states, such as topological states, superconductivity, charge density waves, magnetism, etc., which require atomic-scale heterostructure fabrication. Monolayer FeSe on SrTiO3 substrates has attracted intense interest owing to its remarkable interface-enhanced superconductivity.