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S. S. Kharintsev

Publications and source records attributed to S. S. Kharintsev.

2 recordsLinked to original sources
arXiv2025

Off-Resonance Enhancement of the Refractive Index via Indirect Optical Transitions

At resonance, the optical response of a homogeneous medium to incident light is governed by temporal dispersion, which induces changes in the refractive index (RI). However, recent experimental results reveal RI enhancements exceeding the fundamental limit of 5 in spatially confined systems. Herein, we study the off-resonance enhancement of RI in sub-5 nm gold nanoparticles using electronic light scattering (ELS). We discuss that the RI driven by the distribution and dynamics of excited-state charge-carriers can be locally boosted through the breaking of spatial symmetry in matter. These findings are critical for optically probing RI variations in spatially confined media using ELS.

physics.optics↗
arXiv2024

Extreme electron-photon interaction in perovskite glass

The interaction of light with solids can be dramatically enhanced owing to electron-photon momentum matching. This mechanism is driven by either quantum confinement or long-range structural correlations in media with crystal-liquid duality. In this paper, we address a new strategy based on both phenomena for enhancement of the light-matter interaction in a direct bandgap semiconductor - lead halide perovskite CsPbBr$_3$ - by using electric pulse-driven structural disorder. The disordered (glassy) state allows the generation of confined photons, and the formation of an electronic continuum of static/dynamic defect states across the forbidden gap (Urbach bridge). Both mechanisms underlie photon-momentum-enabled electronic Raman scattering (ERS) and single-photon anti-Stokes photoluminescence (PL) under sub-band pump. PL/ERS blinking is discussed to be associated with thermal fluctuations of cross-linked [PbBr$_6$]$^{4-}$ octahedra. Time-delayed synchronization of PL/ERS blinking causes enhanced spontaneous emission at room temperature. Our findings indicate the role of photon momentum in enhanced light-matter interactions in disordered and nanostructured solids.

physics.optics↗