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arXiv · 2608.30833

Role of self-coherence in single-electron phase contrast imaging

Christian Kisielowski·Petra Specht·Joerg Jinschek·Stig Helveg
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Abstract

The extension of coherent lattice contrast into the energy loss region in high-resolution transmission electron microscopy (HRTEM) is described by a pulse-like electron-sample interaction in the energy/time uncertainty limit. It generates a wave packet by electron self-interference in any coherent-inelastic scattering event with energy loss. The width of this wave packet is characterized by a self-coherence length ls({\Delta}E) that is predictable because an intrinsic decoherence phase around one radian is set by the expectation value for phase fluctuations. In this case the visibility of interference contrast from a crystalline sample with lattice parameter a is limited by a Rayleigh-like transfer factor P(ls, a) in the self-coherently illuminated sample area. The model is verified by energy-filtered HRTEM images of hexagonal BN and identifies energy-loss-induced phase noise as a single-electron visibility limit distinct from resolution limitations caused by ensemble-coherence or counting-statistical noise.

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Christian Kisielowski, Petra Specht, Joerg Jinschek, Stig Helveg. 2026-08-31. Role of self-coherence in single-electron phase contrast imaging. https://arxiv.org/abs/2608.30833

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