作者：Zhang, Yichao; Ahammed, Ballal; Bae, Sang Hyun; Lee, Chia-Hao; Huang, Jeffrey; Hossain, Mohammad Abir; Rakib, Tawfiqur; van der Zande, Arend M.; Ertekin, Elif; Huang, Pinshane Y.
作者单位：University of Illinois System; University of Illinois Urbana-Champaign; University of Illinois System; University of Illinois Urbana-Champaign; University System of Maryland; University of Maryland College Park; University of Illinois System; University of Illinois Urbana-Champaign; University of Illinois System; University of Illinois Urbana-Champaign
摘要：Twisted two-dimensional materials exhibit distinctive vibrational modes called moir & eacute; phonons, which arise from the moir & eacute; superlattice. Here, we demonstrate atom-by-atom imaging of phasons, an ultrasoft class of moir & eacute; phonons in twisted bilayer tungsten diselenide (WSe2). Using ultrahigh-resolution (<15 picometers) electron ptychography, we imaged the size and shape of each atom to extract time-averaged vibrational amplitudes as a function of twist angle and position....
