arXiv subjects

S. Galovic

Publications and source records attributed to S. Galovic.

5 recordsLinked to original sources

arXiv2026

Coherent migration of the single excitation injected into finite-length segment of the biomolecular chain

We study the migration of a single excitation excited at a structural element of a finite molecular segment, which is a part of a long biomolecular chain. The excitation cannot leave the segment and is locally coupled to thermal vibrations of the lattice, forming a self-trapped state corresponding to a nonadiabatic polaron. The time-dependent probability distribution of finding the excitation at the nodes of the segment is calculated, with particular emphasis on the role of the initial excitation position. A formal analogy is observed between the present model and continuous-time quantum walk models on finite chains with reflecting boundaries. The results reveal an asymmetry in the probability distribution for nodes symmetrically positioned with respect to the initially excited site, which arises solely from the asymmetric placement of the initial excitation within the finite segment. The only exception occurs when the initially excited node is located at the center of the segment, where the probability distribution becomes symmetric. The complex interference pattern and the absence of well-defined revivals stem from the non-equidistant spectrum of mode frequencies, leading to progressive dephasing of the constituent modes. As a result, the initially well-localized probability maximum fragments into one dominant maximum accompanied by several secondary maxima of lower intensity. These findings highlight the importance of boundary conditions and initial-state geometry in controlling quantum transport in finite molecular systems.

cond-mat.other↗

arXiv2025

Microwave pulse transparency in Flux-qubit based superconducting quantum metamaterial

We consider the propagation of a classical microwave pulse through a simple setup of a quantum metamaterial composed of a large number of three-Josephson-junction flux qubits. We find that population inversion and electromagnetic waves propagate together as two-component nonlinear waves, exhibiting distinct features depending on the initial preparation of the qubit subsystem and the strength of the "matter"-light interaction. Three different regimes are observed. In the limit of weak nonlinearity, when all qubits are initially prepared in either the clockwise or counterclockwise persistent current state, population inversion undergoes coherent Rabi-like oscillations, with a complete transfer between these two opposite states. As nonlinearity approaches unity, the transition dynamics lose their oscillatory nature, and the system rapidly becomes frozen in a state of zero population inversion, where each qubit is trapped in a superposition with equal probabilities of clockwise and counterclockwise polarity. In the overcritical regime, population inversion exhibits pulsating behavior, but without complete transfer. In the extreme coupling limit, population inversion undergoes small-amplitude oscillations around its initial value, while the pulse amplitude oscillates around zero, indicating pulse stopping.

cond-mat.other↗

arXiv2018

On the vibron nature in the system of two parallel macromolecular chains: the influence of interchain coupling

We studied the properties of the intramolecular vibrational excitation (vibron) at finite temperature in a system which consists of two parallel macromolecular chains. It was assumed that vibron interacts exclusively with dispersionless optical phonons and the whole system is considered to be in thermal equilibrium. Particular attention has been paid to the examination of the impact of the temperature and strength of the interchain coupling on the \emph{small polaron} crossover. For that purpose we employed partial dressing method which enables the study of the degree of the phonon dressing of the vibron excitations in a wide area of system parameter space. We found that in the non--adiabatic regime the degree of dressing as a function of coupling constant continuously increases reflecting the smooth transition of the slightly dressed, practically free vibron, to a heavily dressed one: small polaron. As "adiabaticity" rises this transition becomes increasingly steeper, and finally, in the adiabatic limit, a discontinuous "jump" of the degree of dressing is observed. The interchain coupling manifests itself through the increase of the effective adiabatic parameter of the system.

cond-mat.mes-hall↗

arXiv2018

On the vibron-polaron damping in quasi 1D macromolecular chains

The properties of the intramolecular vibrational excitation (vibron) in a quasi 1D macromolecular structure are studied. It is supposed that due to the vibron interaction with optical phonon modes, a vibron might form partially dressed small polaron states. The properties of these states are investigated in dependence on the basic system parameters and temperature of a thermal bath. We also investigate the process of damping of the polaron amplitude as a function of temperature and vibron-phonon coupling strength. Two different regimes of the polaron damping are found and discussed.

cond-mat.mes-hall↗

arXiv2012

Vibron Self--trapped States in Biological Macromolecules: Comparison of Different Theoretical Approaches

A study of the applicability of the variational treatments based on using of the modified Lang-Firsov unitary transformation (MLF method) in the investigation of the vibron self-trapped states in biological macromolecular chains are presented. We compare the values of the ground state energy predicted by MLF methods with the values of the ground state energy predicted by the standard small-polaron theory, for various values of the basic energy parameters of the system. We obtain regions in system parameter space where MLF approach gives better description of the vibron states.

cond-mat.mes-hall↗