@article{1d10ec98ae4d463993f72f5af8e42f70,
title = "Fast quantum interferometry at the nanometer and attosecond scales with energy-entangled photons",
abstract = "In classical optical interferometry, loss and background complicate achieving fast nanometer-resolution measurements with illumination at low light levels. Conversely, quantum two-photon interference is unaffected by loss and background, but nanometer-scale resolution is physically difficult to realize. As a solution, we enhance two-photon interference with highly nondegenerate energy entanglement featuring photon frequencies separated by 177 THz. We observe measurement resolution at the nanometer (attosecond) scale with only O(104) photon pairs, despite the presence of background and loss. Our nondestructive thickness measurement of a metallic thin film agrees with atomic force microscopy, which often achieves better resolution via destructive means. With contactless, nondestructive measurements in seconds or faster, our instrument enables metrological studies in optically challenging contexts where background, loss, or photosensitivity are factors.",
author = "Lualdi, {Colin P.} and Johnson, {Spencer J.} and Michael Vayninger and Meier, {Kristina A.} and Swetapadma Sahoo and Bogdanov, {Simeon I.} and Kwiat, {Paul G.}",
note = "We thank K. A. Walsh and J. A. N. T. Soares for the assistance with sample characterization; B. Williams, J. Lukens, R. Bennink, and W. Grice at Oak Ridge National Laboratory for the initial development of the entanglement source; and J. N. Eckstein, T. Stelzer, E. A. Goldschmidt, V. O. Lorenz, S. Kundu, and S. Kurdzia\u0142ek for helpful discussions. This work was carried out in part in the Materials Research Laboratory Central Research Facilities, University of Illinois. This material is based on work supported by the U.S. Air Force under grant no. FA9550-21-1-0059 (P.G.K., C.P.L., S.J.J., M.V., and K.A.M.), by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research under Award Number DE-SC0023167 (P.G.K., C.P.L., S.J.J., S.I.B., and S.S.), and by the National Science Foundation Graduate Research Fellowship Program under grant no. DGE 21-46756 (C.P.L.). Portions of this work have been funded by the U.S. Government. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the U.S. Air Force, the U.S. Department of Energy, the National Science Foundation, or the U.S. Government.",
year = "2025",
month = may,
day = "23",
doi = "10.1126/sciadv.adw4938",
language = "English (US)",
volume = "11",
journal = "Science Advances",
issn = "2375-2548",
publisher = "American Association for the Advancement of Science",
number = "21",
}