Fig. 1: Cross-polarized two-photon photoemission traces of a Ag(110) and a polycystalline silver surface.
From: Coherent response of the electronic system driven by non-interfering laser pulses
a Energy- and momentum-integrated cross-correlation traces on Ag(110) (top) and polycrystalline silver (bottom) showing interference patterns despite the non-interfering pump-probe excitation scheme. The black dashed curve represents the expected behavior in the case of a free electron gas. b Schematic of the coupling between the perpendicular electric fields and the optical transition dipole \(\overrightarrow{\mu }\), which leads to coherent photoexcitation for the field components overlapping with the dipole.
