Malyshev, AndreyKnoeste, J.2023-06-202023-06-202007-02-230031-900710.1103/PhysRevLett.98.087401https://hdl.handle.net/20.500.14352/52167©American Physical Society. This work was supported by the programs Ramón y Cajal (Ministerio de Ciencia y Tecnología de España) and NanoNed (Dutch Ministry of Economic Affairs).We argue that the time-resolved spectrum of selectively-excited resonance fluorescence at low temperature provides a tool for probing the quantum-mechanical level repulsion in the Lifshits tail of the electronic density of states in a wide variety of disordered materials. The technique, based on detecting the fast growth of a fluorescence peak that is redshifted relative to the excitation frequency, is demonstrated explicitly by simulations on linear Frenkel exciton chains.engjournal articlehttp://dx.doi.org/10.1103/PhysRevLett.98.087401https://journals.aps.orgopen access538.9Localized frenkel excitonsLinear-chainsDynamicsRelaxationDiffusionFísica de materialesFísica del estado sólido2211 Física del Estado Sólido