arXiv subjects

Slobodanka Galovic

Publications and source records attributed to Slobodanka Galovic.

4 recordsLinked to original sources

arXiv2026

Operator-Level Description of Transient Thermal Grating Dynamics Across Transport Regimes

Transient thermal grating (TTG) experiments provide a powerful means of probing material properties and resolving their dynamics at small spatio-temporal scales through the temporal response to a spatially periodic excitation. However, quantitative interpretation of the measured transient requires a forward model that consistently connects energy deposition, subsequent transport, and detection within the finite space-time window of the experiment, for which such a formulation is still lacking in TTG. Here, we formulate a continuum, operator-based TTG forward model in which the physical processes from energy deposition to detection of the evolving spatial mode are treated within a unified transfer-function framework. Thermal transport dynamics is represented by a temporal memory kernel, allowing unresolved relaxation processes to be incorporated at the scale of experimental observability without imposing an a priori microscopic transport mechanism. The formulation provides a basis for inferring effective material properties and the dynamics resolved within the experimental window, which can subsequently be related to material-specific microscopic degrees of freedom and their interactions. In addition, analysis of the resulting TTG transients shows that the observability of flux memory is not equivalent to the presence of oscillations in the measured response. Oscillations provide a clear signature when finite flux-relaxation dynamics becomes resolved on the experimental time scale, whereas their absence does not imply the Fourier limit. Memory can instead remain observable through non-oscillatory modifications of the transient shape and characteristic time scales.

physics.app-ph↗

arXiv2025

Analytical Model of Resonant Quantum Excitation Transport in Molecular Chains at finite Temperatures: Application of Integral Transforms

This study investigates the potential impact of intramolecular excitations on the active regions of biomolecular chains, which may play a role in physiological processes within living cells. We assumed that an excitation localized in a specific chain segment can modify its physical properties (e.g., local charge distribution or electric dipole moments), thereby altering its role in biochemical processes. As a consequence, the biochemical functionality of the molecular chain may be altered, or even disrupted. Moreover, quantum resonance effects may cause an excitation induced at one structural element to delocalize and appear at a distant site, potentially affecting the functionality of regions located far from the site where the excitation was initially induced. To investigate this phenomenon, we developed and analyzed a theoretical model in which a single excitation is induced in a particular structural element of a finite molecular chain in thermal equilibrium with its environment. The interaction between the excitation and the thermal oscillations of the chain was taken into account. Differential equations for the correlation functions were derived and solved analytically using integral transformations, providing information on the probability of finding the excitation at each site of the chain. The results show that both the probability of finding the excitation at distant sites and its residence time depend on the chain's physical characteristics, temperature, and initial excitation location.

cond-mat.other↗

arXiv2024

Single excitation migration in molecular chain with an attached molecular structure: non-adiabatic polaron model

In this paper we consider the possibility of the stable migration of the single vibron excitation in the system consisting of biomolecule and the attached molecular structure. The model is based on the assumption of the vibron self-trapping and the formation of the non-adiabatic polaron quasiparticle. We have shown that, contrary to the prediction of the non-polaron model, the excitation appears on a large intramolecular distance from its origin with a high probability.

cond-mat.mes-hall↗

arXiv2013

On the vibron dressing in the $α$--helicoidal macromolecular chains

We present a study of the physical properties of the vibrational excitation in $α$--helicoidal macromolecular chains, caused by the interaction with acoustical and optical phonon modes. The influence of the temperature and the basic system parameters on the vibron dressing has been analyzed by employing the simple mean--field approach based on the variational extension of the Lang--Firsov unitary transformation. Applied approach predicts a region in system parameter space where one takes place an abrupt transition from partially dressed (light and mobile) to fully dressed (immobile) vibron states. We found that the boundary of this region depends on system temperature and type of bond among structural elements in the macromolecular chain.

physics.chem-ph↗