Limitations of entangled two-photon absorption detection Pollmann, René Roeder, Franz Silberhorn, Christine Brecht, Benjamin We introduce a method for determining the sensitivity of any given entangled two-photon absorption (ETPA) measurement. By modeling all signal and noise contributions to the measurement, we derive a single numerical value that describes the sensitivity of the ETPA measurement in Göppert-Mayer units. This allows us to directly compare vastly different experimental approaches and determine whether ETPA will be detectable under the given conditions. Therefore we can quantify the effect of any change to a given experimental apparatus and identify the ideal optimization pathway. American Physical Society (APS) 2026 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/66583 Pollmann R, Roeder F, Silberhorn C, Brecht B. Limitations of entangled two-photon absorption detection. <i>Physical Review A</i>. 2026;114(1). doi:<a href="https://doi.org/10.1103/qpb1-hk5l">10.1103/qpb1-hk5l</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1103/qpb1-hk5l info:eu-repo/semantics/altIdentifier/issn/2469-9926 info:eu-repo/semantics/altIdentifier/issn/2469-9934 info:eu-repo/semantics/openAccess