High-harmonic generation articles from across Nature Portfolio

The concept of chiral topological light—a polychromatic light with chiral closed 3D polarization trajectories, space-varying with the azimuthal angle—is introduced and used for efficient sensing in chiral molecules, showcasing an example of successful application of topological concepts in optics.

Fundamental electron-holograms in the single-cycle limit are clearly unveiled to identify electron Gouy-phase and extract the internuclear separation.

The advent of isolated attosecond XUV pulse sources marks a new era in attosecond science, pivotal for the investigation of core electron dynamics. Here the authors discover that the coherent Raman coupling between the cation states leads to extra timedelay between different transition channels by applying the attosecond transient absorption spectroscopy on the investigation of complex dynamics of strong field ionization of Krypton.

High Harmonic Generation in solids differs with respect to its atomic counterpart due to additional intraband harmonic emissions and to the presence of momentum scattering. The authors demonstrate that the additional intraband contribution depends on the momentum distribution of photodoped carriers when the driving pulse arrives to the sample.

High harmonic generation has long been successfully described using the semi-classical three-step model. However, recent progress has introduced a quantum optical formulation, exposing the limitations of the semi-classical picture.

Polycrystalline films of the non-toxic element bismuth exhibit a room-temperature surface nonlinear Hall effect, which could make devices based on topological quantum effects more practical.

Generating high harmonics or attosecond pulses of light is normally thought of as a classical process, but a theoretical study has now shown how the process could be driven by quantum light.

The interaction of atoms with intense squeezed light is affected by the quantum noise of the driving field whereby the quantum noise of the squeezed driving field is imprinted in the emitted high harmonics.

Strongly laser-driven quantum correlated many-body systems lead to the generation of light with exotic quantum features — the quantumness of a many-body system is imprinted on the state of the emitted light.

The presence of topologically protected edge states is usually determined by angular-resolved photoelectron spectroscopy, requiring clean surfaces and ultrahigh vacuum. Now, an all-optical technique, based on high-harmonic radiation, has been shown to detect topological phase transitions under ambient conditions.