Datensatz

Zusammenfassung

We explore the spatial coherence of double-gate single nanotip field emitters by low-energy electron diffraction experiments in transmission mode. By producing collimated field emission pulses from the single nanotip cathode and irradiating a suspended monolayer graphene film without additional optics, we observed sharper and higher resolution Bragg diffraction spots than a previous experiment using a nanotip array cathode. In particular, we found complete conservation of the size and the shape of the diffraction spots with those of the incident beam on the sample. The result indicates that the transverse coherence of a nanofabricated double-gate single-tip emitter is much larger than a few nanometers as determined by the apparent diffraction spot size and overall spatial resolution of the observed diffraction pattern.