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A look under the tunnelling barrier via attosecond-gated interferometry


Interferometry has been at the heart of wave optics since its early stages, resolving the coherence of the light field and enabling the complete reconstruction of the optical information it encodes. Transferring this concept to the attosecond time domain shed new light on fundamental ultrafast electron phenomena. Here we introduce attosecond-gated interferometry and probe one of the most fundamental quantum mechanical phenomena, field-induced tunnelling. Our experiment probes the evolution of an electronic wavefunction under the tunnelling barrier and records the phase acquired by an electron as it propagates in a classically forbidden region. We identify the quantum nature of the electronic wavepacket and capture its evolution within the optical cycle. Attosecond-gated interferometry has the potential to reveal the underlying quantum dynamics of strong-field-driven atomic, molecular and solid-state systems.

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Fig. 1: Attosecond-gated interferometry.
Fig. 2: Mapping the attosecond gating into the complex XUV field.
Fig. 3: Probing the tunnelling dynamics.

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Data availability

The main data supporting the findings of this study are available within the article and its Supplementary Information. Extra data are available from the corresponding author upon reasonable request.

Code availability

The codes that support the findings of this study are available from the corresponding author upon reasonable request.


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We thank D. Tannor, Y. Mairesse and B. Pons for helpful discussions. N.D. is the incumbent of the Robin Chemers Neustein Professorial Chair. N.D. acknowledges the Minerva Foundation, the Israeli Science Foundation, the Crown Center of Photonics and the European Research Council for financial support. M.I. and O.S. acknowledge support from the DFG SPP 1840 ‘Quantum Dynamics in Tailored Intense Fields’, DFG grants SM 292/5-2 and IV 152/6-2. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 899794. O.K. acknowledges the Azrieli Foundation for the award of an Azrieli Fellowship. M.K. acknowledges financial support by the Minerva Foundation and the Koshland Foundation. D.A. acknowledges financial support by the Zuckerman STEM Leadership Program.

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Authors and Affiliations



N.D., M.I., O.S. and S.P. supervised the study. O.K., D.A., M.K. and N.D. conceived and designed the experiments. O.K., D.A. and M.K. built the experimental setup. O.K. and Y.F. performed the measurements and analysed the data. O.K. developed and performed the ARM theoretical calculations, supervised by M.I., O.S., S.P. and N.D. The TDSE theoretical calculations were conceived and performed by S.P. Operation of the laser system was supported by B.D.B. All authors interpreted the experimental and theoretical results, discussed the results and contributed to the final manuscript.

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Correspondence to Nirit Dudovich.

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Nature Photonics thanks the anonymous reviewers for their contribution to the peer review of this work.

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Supplementary Sections 1–10 and Figs. 1–15.

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Kneller, O., Azoury, D., Federman, Y. et al. A look under the tunnelling barrier via attosecond-gated interferometry. Nat. Photon. 16, 304–310 (2022).

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