Preparation of two-dimensional superconductors: a comprehensive review

Abstract

Recently, two-dimensional (2D) superconductors, including 2D van der Waals crystals, few-layer cuprates, and iron-based interfacial superconductors, have attracted much attentions. Benefiting from advances in the manufacturing process, these 2D superconductors with precise atomic compositions, highly crystalline structures, ultra-flat surfaces and ultra-clean interfaces exhibit a wealth of novel physical properties, such as Ising superconductivity, high-temperature superconductivity, topological superconductivity, etc., which provide an ideal platform for exploring superconductors with higher transition temperatures and critical fields. In this review, we sort out the timeline and categorize various types of 2D superconductors from recent studies, highlighting the preparation methods of these superconductors, such as, mechanical exfoliation, molecular beam epitaxy, pulsed laser deposition, and especially the chemical vapour deposition. Finally, we conclude with future research directions and prospects in preparation of 2D superconducting materials.