@article{WallKrenzerWippermannetal., author = {Wall, Simone and Krenzer, Boris and Wippermann, Stefan and Sanna, Simone and Klasing, Friedrich and Hanisch-Blicharski, Anja and Kammler, Martin and Schmidt, Wolf Gero and Horn-von Hoegen, Michael}, title = {Atomistic picture of charge density wave formation at surfaces}, series = {Physical review letters}, volume = {109}, journal = {Physical review letters}, number = {18}, publisher = {APS}, doi = {10.1103/PhysRevLett.109.186101}, abstract = {We used ultrafast electron diffraction and density-functional theory calculations to gain insight into the charge density wave (CDW) formation on In/Si(111). Weak excitation by a femtosecond-laser pulse results in the melting of the CDW. The immediate freezing is hindered by a barrier for the motion of atoms during the phase transition: The melted CDW constitutes a long-lived, supercooled phase and is strong evidence for a first-order transition. The freezing into the CDW is triggered by preexisting adsorbates. Starting at these condensation nuclei, the CDW expands one dimensionally on the In/Si(111) surface, with a constant velocity of more than 80 m/s.}, language = {en} }