Imaging the graphene electron motion in real time and space

Ultrafast Electron Diffraction and Microscopy imaging have been demonstrated to be pivot tools for imaging the atomic motion in real-time and space[1-3]. The generation of a few hundred femtoseconds electron pulses enabled recording movies for molecular and atomic motion. However, the technical challenges in electron pulse compression have limited the temporal resolution of electron imaging experiments to a hundred femtoseconds. Here, we demonstrate the attosecond temporal resolution by generating attosecond electron pulses in the transmission electron microscope to establish what we so-called “Attomicroscopy”. Moreover, we utilized the Attomicroscopy to image the electron motion dynamics in graphene. In a strong field, the electron is moving in the reciprocal space around the Dirac point following the waveform of the driver field. The attosecond electron diffraction experiment allowed us to extract the electron density distribution in the reciprocal space at different time instants and connect it with the electron motion in real space. The demonstrated Attomicroscopy imaging tool opens the avenue to study electron motion in neutral matter and promises new electron imaging applications in physics, chemistry, and biochemistry.

References

1. [1] M. T. Hassan, J. Phys. B: At. Mol. Opt. Phys. 51, 032005 (2018).
   
   [2] R. J. D. Miller, Science 343, 1108 (2014).
   
   [3] A. H. Zewail, Science 328, 187 (2010).