Atomically thin cuprates exhibiting a superconducting phase transition temperature similar to bulk have recently been realized, although the device fabrication remains a challenge and limits the potential for many novel studies and applications. Here we use an optical pump-probe approach to noninvasively study the unconventional superconductivity in atomically thin Bi2Sr2Ca0.92Y0.08Cu2O8+δ (Y-Bi2212). Apart from finding an optical response due to the superconducting phase transition that is similar to bulk Y-Bi2212, we observe that the sign and amplitude of the pump-probe signal in the atomically thin flake vary significantly in different dielectric environments depending on the nature of the optical excitation. By exploiting the spatial resolution of the optical probe, we uncover the exceptional sensitivity of monolayer Y-Bi2212 to the environment. Our results provide the first optical evidence for the intralayer nature of the superconducting condensate in Bi2212, and highlight the role of double-sided encapsulation in preserving superconductivity in atomically thin cuprates.
@article{arxiv.2403.04136,
title = {Optically Probing Unconventional Superconductivity in Atomically Thin Bi$_2$Sr$_2$Ca$_{0.92}$Y$_{0.08}$Cu$_2$O$_{8+{\delta}}$},
author = {Yunhuan Xiao and Jingda Wu and Jerry I Dadap and Kashif Masud Awan and Dongyang Yang and Jing Liang and Kenji Watanabe and Takashi Taniguchi and Marta Zonno and Martin Bluschke and Hiroshi Eisaki and Martin Greven and Andrea Damascelli and Ziliang Ye},
journal= {arXiv preprint arXiv:2403.04136},
year = {2024}
}