arXiv subjects

Adina Golombek

Publications and source records attributed to Adina Golombek.

6 recordsLinked to original sources

arXiv2026

Cavity-Mediated Long-Range Cooperative Coupling between Localized Plasmons and Molecular Excitons

Strong coupling between molecules and electromagnetic fields has emerged as a powerful strategy to modify the physical and chemical properties of molecules, enabled by the formation of hybridized energy levels through strong light-matter interactions. Rather than purely photonic or plasmonic modes, hybrid cavity fields that integrate plasmonic and photonic contributions provide versatile platforms with distinct advantages for tailoring light-matter interactions. Here, we present hybrid modes formed through the coupling between localized surface plasmon resonances of Au nanoparticles and Fabry-Perot microcavity modes. Furthermore, by using this hybrid platform, we demonstrate that the cavity field can give rise to cooperative coherent coupling between the spatially separated plasmonic nanoparticles and the molecules by mediating long-range dipole-dipole interactions. As we show, this cavity-mediated coupling also enhances the plasmon-exciton mixing, as compared to their direct interaction. This configuration opens new avenues for tailoring light-matter interactions at the nanoscale by supporting novel hybrid plexcitonic states that incorporate contributions from plasmons, excitons, and extended cavity fields.

physics.optics↗

arXiv2023

Enhanced transmission at the zeroth-order mode of a terahertz Fabry-Perot cavity

A planar Fabry-Perot cavity with inter-mirror spacing significantly shorter than the probing wavelength is explored for its "zero-order mode" terahertz transmission. The enhanced transmission observed as d approaches 0 indicates that such cavities satisfy the resonance condition across a broad terahertz bandwidth. The experimental signatures from this elusive, "technically challenging" regime are evidenced using time-domain terahertz spectroscopy and are complemented by numerical calculations. The results raise intriguing possibilities for terahertz field modulation and pave new paths for strong coupling of multiple transition frequencies simultaneously.

physics.optics↗

arXiv2023

Intramolecular Structural Heterogeneity altered by Long-range Contacts in an Intrinsically Disordered Protein

Short-range interactions and long-range contacts drive the 3D folding of structured proteins. The proteins' structure has a direct impact on their biological function. However, nearly 40% of the eukaryotes proteome is composed of intrinsically disordered proteins (IDPs) and protein regions that fluctuate between ensembles of numerous conformations. Therefore, to understand their biological function, it is critical to depict how the structural ensemble statistics correlate to the IDPs' amino acid sequence. Here, using small-angle x-ray scattering (SAXS) and time-resolved Förster resonance energy transfer (trFRET), we study the intra-molecular structural heterogeneity of the neurofilament low intrinsically disordered tail domain (NFLt). Using theoretical results of polymer physics, we find that the Flory scaling exponent of NFLt sub-segments correlates linearly with their net charge, ranging from statistics of ideal to self-avoiding chains. Surprisingly, measuring the same segments in the context of the whole NFLt protein, we find that regardless of the peptide sequence, the segments' structural statistics are more expanded than when measured independently. Our findings show that while polymer physics can, to some level, relate the IDP's sequence to its ensemble conformations, long-range contacts between distant amino acids play a crucial role in determining intra-molecular structures. This emphasizes the necessity of advanced polymer theories to fully describe IDPs ensembles with the hope it will allow us to model their biological function.

physics.bio-ph↗

arXiv2022

Unveiling the mixed nature of polaritonic transport: From enhanced diffusion to ballistic motion approaching the speed of light

In recent years it has become clear that the transport of excitons and charge carriers in molecular systems can be enhanced by coherent coupling with photons, giving rise to the formation of hybrid excitations known as polaritons. Such enhancement has far-reaching technological implications, however, the enhancement mechanism and the transport nature of these composite light-matter excitations in such systems still remain elusive. Here we map the ultrafast spatiotemporal dynamics of surface-bound optical waves strongly coupled to a self-assembled molecular layer and fully resolve them in energy/momentum space. Our studies reveal intricate behavior which stems from the hybrid nature of polaritons. We find that the balance between the molecular disorder and long-range correlations induced by the coherent mixing between light and matter leads to a mobility transition between diffusive and ballistic transport, which can be controlled by varying the light-matter composition of the polaritons. Furthermore, we directly demonstrate that the coupling with light can enhance the diffusion coefficient of molecular excitons by six orders of magnitude and even lead to ballistic flow at two-thirds the speed of light.

cond-mat.mtrl-sci↗

arXiv2019

Collective Rayleigh Scattering from Molecular Ensembles under Strong Coupling

Rayleigh scattering is usually considered to be the elastic scattering of photons from sub-wavelength physical objects, such as small particles or molecules. Here, we present the spectroscopic study of the scattering properties of molecules embedded in an optical cavity under strong coupling conditions, where the collective interaction between the molecules and the cavity gives rise to composite light-matter excitations known as cavity polaritons. We show that the polaritonic states exhibit strong resonant Rayleigh scattering, reaching 25% efficiency. Since the polaritonic wavefunctions in such systems are delocalized, our observations correspond to the collective scattering of each photon from a large ensemble of molecules.

quant-ph↗

arXiv2019

Strong Coupling of Light to Collective Terahertz Vibrations in Organic Materials

Several years ago, it was shown that strong coupling between an electronic transition in organic molecules and a resonant photonic structure can modify the electronic landscape of the molecules and affect their chemical behavior. Since then, this new concept has evolved into a new field known as polaritonic chemistry, which employs strong coupling as a new tool for controlling material properties and molecular chemistry. An important ingredient in the progress of this field was the recent demonstration of strong coupling of molecular vibrations to mid-infrared resonators, which enabled the modification of chemical processes occurring at the electronic ground-state of materials. Here we demonstrate for the first time strong coupling with collective, intermolecular vibrations occurring in organic materials in the Terahertz frequency region. Using a tunable, open-cavity geometry, we measure the temporal evolution and observe coherent Rabi oscillations, corresponding to a splitting of 68 GHz and approaching the ultra-strong coupling regime. These results take strong light-matter coupling into a new class of materials, including polymers, proteins and other organic materials, in which collective, spatially extended degrees of freedom participate in the dynamics.

quant-ph↗