Optical control of decoherence in electron grating diffraction
Using the above band-gap photoexcitation, we created a charge pattern on a GaAs surface. The Coulomb interaction between a free electron and the charge structure results in the decoherence of the free-electron wavepakcet, as evidenced by the broadening of the diffraction peak width; a broadened width implies a decrease in the electron’s transverse coherence length. The strength of decoherence can be controlled through the excitation laser applied to the GaAs plate and the relative distance between the electron beam and the plate. As only one electron is present in the vacuum chamber at any time, we have demonstrated a controllable open quantum system for single electrons. In this talk, I will present some recent experimental results and discuss a possible decoherence mechanism based on entanglement.
Host: Gretchen Campbell