Strong-Field Perspective on High Harmonic Radiation from Bulk Solids

01.01.2016, 00:00

Newsletter 9

To record the dynamics of a fast moving object, short pulses of light are used to record a series of "frozen" pictures. In the case of electrons in materials, typical timescales are of the order of attoseconds (a billionth of a billionth of a second), so that attosecond light pulses are required. So far they have been generated as high-harmonics of a strong laser pulse in gaseous media. In this study, we propose to generate such extremely short pulses in a solid-state medium, opening up the prospect of a compact solid-state device. To this end, we have clarified theoretically the mechanisms of high-harmonic generation from crystals by treating the electric field of a laser as a quasi-static strong field. Under these circumstances, electrons in periodic potentials form dressed states, known as Wannier-Stark states. The energy differences between the dressed states determine the frequencies of the radiation. The radiation yield is determined by the magnitudes of the current matrix elements between the dressed states. With a proper high-frequency filter an extremely short part of the radiation, reaching the attosecond timescale, can be extracted.

Contact: peter.hommelhoff(at)physik.uni-erlangen(dot)depeter.hommelhoff(at)physik.uni-erlangen(dot)de
Group: Peter Hommelhoff Group (FAU) (associated with MPL)
Reference: T. Higuchi, et al., Phys. Rev. Lett. 113, 213901 (2014).