Connection between coherent phonons and electron-phonon coupling in Sb (111)

We report time- and angle-resolved photoemission spectroscopy (trARPES) measurements on the Sb(111) surface. We observe band- and momentum-dependent binding-energy oscillations in the bulk and surface bands driven by A(1g) and E-g coherent phonons. While the bulk band shows simultaneous A(1g) and E-g oscillations, the surface bands show either A(1g) or E-g oscillations. The observed behavior is reproduced by frozen-phonon calculations based on density functional theory. This evidences the connection between electron-phonon coupling and coherent binding-energy dynamics tied to lattice vibration and confirms that band-, momentum-, and mode-dependent electron-phonon coupling can indeed be probed by trARPES in the low fluence limit.