2015/07/01 by M. Hohenleutner, F. Langer, O. Schubert +7 · 631 citations
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #Attosecond #Bloch oscillations #Electron #High harmonic generation #Laser #Laser-Matter Interactions and Applications #Optics #Physics #Quantum mechanics #Terahertz technology and applications #Ultrashort pulse #cond-mat.mes-hall #physics.optics
paper · pdf · doi:10.1038/nature14652
published in Nature 523(7562), 572-575 (Nature Portfolio)
openalex publication_date 2015/07/01 · arxiv created 2016/04/13 · arxiv updated 2016/04/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Accelerating and colliding particles has been a key strategy to explore the texture of matter. Strong lightwaves can control and recollide electronic wavepackets, generating high-harmonic (HH) radiation which encodes the structure and dynamics of atoms and molecules and lays the foundations of attosecond science. The recent discovery of HH generation in bulk solids combines the idea of ultrafast acceleration with complex condensed matter systems and sparks hope for compact solid-state attosecond sources and electronics at optical frequencies. Yet the underlying quantum motion has not been observable in real time. Here, we study HH generation in a bulk solid directly in the time-domain, revealing a new quality of strong-field excitations in the crystal. Unlike established atomic sources, our solid emits HH radiation as a sequence of subcycle bursts which coincide temporally with the field crests of one polarity of the driving terahertz waveform. We show that these features hallmark a novel non-perturbative quantum interference involving electrons from multiple valence bands. The results identify key mechanisms for future solid-state attosecond sources and next-generation lightwave electronics. The new quantum interference justifies the hope for all-optical bandstructure reconstruction and lays the foundation for possible quantum logic operations at optical clock rates.