Chiral topological light for detection of robust enantiosensitive observables.

The topological response of matter to electromagnetic fields is a highly demanded property in materials design and metrology due to its robustness against noise and decoherence, stimulating recent advances in ultrafast photonics. Embedding topological properties into the enantiosensitive optical response of chiral molecules could therefore enhance the efficiency and robustness of chiral optical discrimination. Here we achieve such a topological embedding by introducing the concept of chiral topological light-a light beam which displays chirality locally, with an azimuthal distribution of its handedness described globally by a topological charge.

Imprinting Chirality on Atoms Using Synthetic Chiral Light Fields.

Atoms are usually thought of as achiral objects. However, one can construct superpositions of atomic states that are chiral [1]. Here, we show how to excite such superpositions with tailored light fields both in the weak-field and strong-field regimes, using realistic laser parameters.

Femtosecond Extreme Ultraviolet Photoelectron Spectroscopy of Organic Molecules in Aqueous Solution.

Time-resolved valence photoelectron spectroscopy is an established tool for studies of ultrafast molecular dynamics in the gas phase. Here we demonstrate time-resolved XUV photoelectron spectroscopy from dilute aqueous solutions of organic molecules, paving the way to application of this method to photodynamics studies of organic molecules in natural environments, which so far have only been accessible to all-optical transient spectroscopies. We record static and time-resolved photoelectron spectra of a sample molecule, quinoline yellow WS, analyze its electronic structure, and follow the relaxation dynamics upon excitation with 400 nm pulses.

Interference stabilization of autoionizing states in molecular N studied by time- and angular-resolved photoelectron spectroscopy.

An autoionizing resonance in molecular N is excited by an ultrashort XUV pulse and probed by a subsequent weak IR pulse, which ionizes the contributing Rydberg states. Time- and angular-resolved photoelectron spectra recorded with a velocity map imaging spectrometer reveal two electronic contributions with different angular distributions. One of them has an exponential decay rate of 20 ± 5 fs, while the other one is shorter than 10 fs.