Attosecond tunnelling interferometry

• Published in: Nature physics Vol. 11; no. 10; pp. 815 - 819
• Main Authors: Pedatzur, O., Orenstein, G., Serbinenko, V., Soifer, H., Bruner, B. D., Uzan, A. J., Brambila, D. S., Harvey, A. G., Torlina, L., Morales, F., Smirnova, O., Dudovich, N.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.10.2015; Nature Publishing Group
• Subjects: 639/624/400/3923; 639/624/400/584; 639/766/36/2796; Atomic; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; Electronics; Evolution; Interferometry; Ionization; Lasers; letter; Mathematical and Computational Physics; Molecular; Optical and Plasma Physics; Physics; Potential barriers; Temporal logic; Theoretical; Time; Tunnelling; Wavefunctions
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/nphys3436

An interferometric measurement based on high-harmonic generation now provides direct access to the electron wavefunction during field-induced tunnelling. Attosecond physics offers new insights into ultrafast quantum phenomena involving electron dynamics on the fastest measurable timescales. The rapid progress in this field enables us to re-visit one of the most fundamental strong-field phenomena: field-induced tunnel ionization 1 , 2 , 3 . In this work, we employ high-harmonic generation to probe the electron wavefunction during field-induced tunnelling through a potential barrier. By using a combination of strong and weak driving laser fields, we modulate the atomic potential barrier on optical subcycle timescales. This induces a temporal interferometer between attosecond bursts originating from consecutive laser half-cycles. Our study provides direct insight into the basic properties of field-induced tunnelling, following the evolution of the electronic wavefunction within a temporal window of approximately 200 attoseconds.