High-Harmonic Spectroscopy through Matter Talbot-Lau Interferometry

High harmonic generation (HHG) provides for an extraordinary tool to unravel the electronic dynamics in the nanometric and sub-femtosecond scales. Recently, the application of high harmonic spectroscopy to solids has been useful to reveal information such as the electronic band structure as well as to probe the electronic wavepacket coherence. Typically, HHG in low-dimensional systems is driven by a linearly polarized laser field directed parallel to the axis or plane. However, it has been found that it is also possible to efficiently generate harmonics when the laser polarization is perpendicular to the target [1] . In this scenario of low-dimensional systems at grazing incidence, there is a parallelism between the ionized electron dynamics and light diffraction [2] , as a consequence of the analogy between the Schrodinger propagator for a free particle and the Fresnel propagator for light. In particular, the well-known Talbot effect can be translated to matter waves, as it has been shown in several occasions in electronic, atomic and Bose-Einstein condensates matter waves.