Perfect Coulomb drag and exciton transport in an excitonic insulator

• DOI: 10.1126/science.adl1839
• Publication Date: 2025-04-17T18:00:31Z
• Authors: Ruishi Qi; Andrew Y. Joe; Zuocheng Zhang; Jingxu Xie; Qixin Feng; Zheyu Lu; Ziyu Wang; Takashi Taniguchi; Kenji Watanabe; Sefaattin Tongay; Feng Wang
• Keywords: Biexciton

Strongly coupled electron-hole bilayers can host quantum states of interlayer excitons, such as high-temperature exciton condensates at zero magnetic field. This state is predicted to feature perfect Coulomb drag, where a current in one layer accompanied by an equal but opposite the other. We used optical technique probe electrical transport correlated based on MoSe 2 /hBN/WSe heterostructures. observed drag excitonic insulator phase low temperatures; counterflow resistance excitons remained finite. These results indicate formation gas that does not condense into superfluid. Our work demonstrates dynamic spectroscopy provides powerful tool for probing behavior fluids.