Nicholson, Christopher W. Lücke, A. Schmidt, W. G. Puppin, M. Rettig, L. Ernstorfer, R. Wolf, M. 2018-11-16 Ultrafast nonequilibrium dynamics offer a route to study the microscopic interactions that govern macroscopic behavior. In particular, photoinduced phase transitions (PIPTs) in solids provide a test case for how forces, and the resulting atomic motion along a reaction coordinate, originate from a nonequilibrium population of excited electronic states. Using femtosecond photoemission, we obtain access to the transient electronic structure during an ultrafast PIPT in a model system: indium nanowires on a silicon(111) surface. We uncover a detailed reaction pathway, allowing a direct comparison with the dynamics predicted by ab initio simulations. This further reveals the crucial role played by localized photoholes in shaping the potential energy landscape and enables a combined momentum- and real-space description of PIPTs, including the ultrafast formation of chemical bonds. application/pdf https://folia.unifr.ch/global/documents/307486 https://folia.unifr.ch/documents/307486/files/nic_bmm.pdf https://folia.unifr.ch/documents/307486/files/nic_bmm_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1126/science.aar4183 info:eu-repo/semantics/openAccess License undefined Science. - 2018, vol. 362, no. 6416, p. 821–825 info:eu-repo/classification/udc/53 Beyond the molecular movie: Dynamics of bands and bonds during a photoinduced phase transition http://purl.org/coar/resource_type/c_6501