Atomically Thin Interfacial High-Temperature Superconductivity

Quantum materials host a vast array of emergent phenomena, including high-temperature superconductivity, topological properties, and nanoscale charge / spin ordering. One of the challenges is to be able to precisely and deterministically manipulate their properties. Here, we describe how superconductivity can be dramatically enhanced in a single monolayer of FeSe, through a combination of advanced materials synthesis and angle-resolved photoemission spectroscopy (ARPES) which provides direct insights into the electronic structure and quantum many-body interactions. While bulk FeSe superconducts at a relatively modest temperature (8 K), our measurements reveal superconducting pairing fluctuations up to 70 K. The dramatic enhancement of superconductivity in a single monolayer of FeSe / SrTiO3 remains the largest amongst known superconductors, positioning this system as an ideal platform for investigating fundamental questions about interfacial superconductivity.