@article{12736,
  author = {Jun Nishida and Samuel Johnson and Peter Chang and Dylan Wharton and Sven Dönges and Omar Khatib and Markus Raschke},
  title = {Ultrafast infrared nano-imaging of far-from-equilibrium carrier and vibrational dynamics},
  abstract = {Ultrafast infrared nano-imaging has demonstrated access to ultrafast carrier dynamics on the nanoscale in semiconductor, correlated-electron, or polaritonic materials. However, mostly limited to short-lived transient states, the contrast obtained has remained insufficient to probe important long-lived excitations, which arise from many-body interactions induced by strong perturbation among carriers, lattice phonons, or molecular vibrations. Here, we demonstrate ultrafast infrared nano-imaging based on excitation modulation and sideband detection to characterize electron and vibration dynamics with nano- to micro-second lifetimes. As an exemplary application to quantum materials, in phase-resolved ultrafast nano-imaging of the photoinduced insulator-to-metal transition in vanadium dioxide, a distinct transient nano-domain behavior is quantified. In another application to lead halide perovskites, transient vibrational nano-FTIR spatially resolves the excited-state polaron-cation coupling underlying the photovoltaic response. These examples show how heterodyne pump-probe nano-spectroscopy with low-repetition excitation extends ultrafast infrared nano-imaging to probe elementary processes in quantum and molecular materials in space and time.},
  year = {2022},
  journal = {Nature Communications},
  volume = {13},
  pages = {1083},
  month = {2022-02},
  url = {https://www.nature.com/articles/s41467-022-28224-9},
}