20.500.12556/RUL-177724 Theory of ultrafast screening of U in driven charge-transfer insulators: a time-resolved x-ray absorption study Recent seminal experiments have utilized time-resolved x-ray absorption spectroscopy (XAS) to investigate the ultrafast photoinduced renormalization of the electron interaction (“Hubbard U”) in Mott and charge transfer insulators. In this paper, we theoretically analyze the change of interactions due to dynamical screening as it is encoded in the XAS signal, using the nonequilibrium GW+EDMFT formalism. Our study shows that XAS is well-suited for measuring this change, but two aspects should be kept in mind if the screening processes are not substantially faster than the valence electron dynamics: (i) Screening in a photoexcited system can affect both the position and the lineshape of the absorption lines. (ii) In general, the effect cannot be captured by the modification of a single interaction parameter. Specifically, an estimate for Δ⁢� extracted from the shift of the XAS lines does not necessarily describe the related shift of the upper Hubbard band. We clarify these aspects using a minimal cluster model and the three-band Emery model for a charge transfer insulator. consensed matter physics nonequilibrium systems Hubbard model X-ray absorption spectroscopy fizika kondenzirane snovi neravnovesni sistemi Hubbardov model rentgenska absorpcijska spektroskopija true false true Angleški jezik Slovenski jezik Članek v reviji 2026-01-05 13:25:09 2026-01-05 13:25:10 2026-01-06 04:17:12 0000-00-00 00:00:00 2025 0 0 Str. 045147-1-045147-15 iss. 4 Vol. 111 2025 0000-00-00 PostprintKoncna Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 538.9 2469-9950 10.1103/PhysRevB.111.045147 233516291 dp_xas.pdf dp_xas.pdf 1 A204BD823247DBF8132C53E43940FC8A 319c8aca91d5350eb7413d857416891661326e25f11c972f20b51c972a1dc32d ecccb53c-ea31-11f0-bf92-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=224962 https://journals.aps.org/prb/abstract/10.1103/PhysRevB.111.045147 0 f421d297-ea31-11f0-bf92-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=224963 Fakulteta za matematiko in fiziko 0 0 0