Международная школа-семинар Экситоны в кристаллах и полупроводниковых наноструктурах", посвященная 120-летию со дня рождения Е. Ф. Гросса, Санкт-Петербург 10-12 октября 2017 года Экситонная спектроскопия полупроводников методом генерации оптических гармоник [1mm] (О б з о р)

Nonlinear optical phenomena are widely used for the study of semiconductor materials. The paper presents an overview of experimental and theoretical studies of excitons by the method of optical second and third harmonics generation in various bulk semiconductors (GaAs, CdTe, ZnSe, ZnO, Cu_2O, (Cd,Mn)Te, EuTe, EuSe), and low-dimensional heterostructures ZnSe/BeTe. Particular attention is paid to the role of external electric and magnetic fields that modify the exciton states and induce new mechanisms of optical harmonics generation. Microscopic mechanisms of harmonics generation based on the Stark effect, the spin and orbital Zeeman effects, and on the magneto-Stark effect specific for excitons moving in an external magnetic field are considered. This approach makes it possible to study the properties of excitons and to obtain new information on their energy and spin structure that is not available when the excitons are investigated by linear optical spectroscopy. As a result of these studies, a large amount of information was obtained, which allows us to conclude on the establishing of a new field of research—exciton spectroscopy by the method of optical harmonics generation.

Jahn–Teller effects in Au25(SR)18

Jahn–Teller distortions are observed in Au25(SR)18 by single crystal X-ray crystallography. SQUID magnetometry, DFT theory, and linear optical spectroscopy corroborate the finding.

Plasmonic oligomers in cylindrical vector light beams

We investigate the excitation as well as propagation of magnetic modes in plasmonic nanostructures. Such structures are particularly suited for excitation with cylindrical vector beams. We study magneto-inductive coupling between adjacent nanostructures. We utilize high-resolution lithographic techniques for the preparation of complex nanostructures consisting of gold as well as aluminium. These structures are subsequently characterized by linear optical spectroscopy. The well characterized and designed structures are afterwards studied in depth by exciting them with radial and azimuthally polarized light and simultaneously measuring their plasmonic near-field behavior. Additionally, we attempt to model and simulate our results, a project which has, to the best of our knowledge, not been attempted so far.