Dynamical theory of angle-resolved electron energy loss and gain spectroscopies of phonons and magnons including multiple scattering effects

We present a method for computing angle-resolved electron-energy-loss and gain spectroscopies for phonon and magnon excitations in transmission electron microscopy. Fractional scattering intensities are derived from the temperature-dependent time auto-correlation of the electron beam wave function. This method captures both single and multiple scattering processes, as well as dynamical diffraction effects. Our method remains computationally efficient, and it is easy to parallelize.