000163248 001__ 163248 000163248 005__ 20251024172258.0 000163248 0247_ $$2doi$$a10.1103/5qnm-zgjt 000163248 0248_ $$2sideral$$a145742 000163248 037__ $$aART-2025-145742 000163248 041__ $$aeng 000163248 100__ $$0(orcid)0000-0001-5939-6415$$aAnadón, Alberto 000163248 245__ $$aLarge spin accumulation signals in ultrafast magneto-optical experiments 000163248 260__ $$c2025 000163248 5060_ $$aAccess copy available to the general public$$fUnrestricted 000163248 5203_ $$aMagneto-optical techniques have become essential tools in spintronics, enabling the investigation of spin dynamics in the ultrafast regime. A key challenge in this field has been to accurately isolate the contributions to magneto-optical signals of spin transport phenomena from the local magnetization dynamics. The contribution of transported and accumulated spins was long believed to be orders of magnitude smaller than that of the magnetization and thus previous approaches to disentangle these signals have relied on specific experimental designs, usually including thick metal layers. Here, we present experimental evidence demonstrating that the magneto-optical signal from ultrafast spin accumulations can, under certain conditions, be comparable to or even exceed that of the magnetic layer in a standard ultrafast demagnetization experiment. Our findings provide a framework for accessing and isolating these spin accumulations, allowing for time- and depth-dependent probing of transported spin and/or orbital angular momentum. 000163248 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/ 000163248 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000163248 700__ $$aSingh, Harjinder 000163248 700__ $$aDíaz, Eva 000163248 700__ $$aLe-Guen, Yann 000163248 700__ $$aHohlfeld, Julius 000163248 700__ $$aWilson, Richard B. 000163248 700__ $$aMalinowski, Gregory 000163248 700__ $$aHehn, Michel 000163248 700__ $$aGorchon, Jon 000163248 773__ $$g112 , 104437 (2025), 9$$pPhys. Rev. B$$tPhysical Review B$$x2469-9950 000163248 8564_ $$s2626742$$uhttps://zaguan.unizar.es/record/163248/files/texto_completo.pdf$$yPostprint 000163248 8564_ $$s2220534$$uhttps://zaguan.unizar.es/record/163248/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000163248 909CO $$ooai:zaguan.unizar.es:163248$$particulos$$pdriver 000163248 951__ $$a2025-10-24-16:55:43 000163248 980__ $$aARTICLE