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arXiv · 2301.02115

Evidence of coherence in strong-field electron photoemission from a semiconductor

Marie Froidevaux·Ludovic Douillard·Willem Boutu·Milutin Kovacev·Philippe Zeitoun·Hamed Merdji
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Abstract

Strong-field quantum electronics is emerging as a potential candidate in information processing but still coherence vs decoherence is a primary concern of the concept. Strong-field coherent processes in band gap materials have led during the last decade to the emergence of high harmonic generation in semiconductors, petahertz electronics, or strong-field quantum states. However, the coherent behavior of the sub-optical cycle-driven electrons has never been directly observed. We report here on the experimental evidence of coherent ultrashort emission of hot electrons from a nanostructured semiconductor. Our method uses sub-wavelength electric field enhancement to localize the electron emission within a nanometer-scale spot. We found similarities with the electron emission from metallic nanotips in the strong-field regime, a topic that has opened a vast domain of applications during the last decade. The electron spectra display both odd and even harmonic orders of the driving femtosecond laser frequency, a signature of the coherent nature of the electron emission and their attosecond timing. Our findings complete our knowledge of phenomena governing coherent strong-field processes in semiconductors and open perspectives for the generation of future quantum devices operating in the strong-field regime.

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Marie Froidevaux, Ludovic Douillard, Willem Boutu, Milutin Kovacev, Philippe Zeitoun, Hamed Merdji. 2023-01-05. Evidence of coherence in strong-field electron photoemission from a semiconductor. https://arxiv.org/abs/2301.02115

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