arXiv subjects

Trilochan Bagarti

Publications and source records attributed to Trilochan Bagarti.

12 recordsLinked to original sources

arXiv2025

Two and three-state quantum heat engines with stochastic resetting

Quantum heat engines have undergone extensive studies over the last two decades. Simultaneously, the studies of the applications of stochastic resetting in various fields are on the rise. We explore the effect of stochastic resetting on the dynamics of a two-level and a three-level quantum heat engine. The extracted work is shown to increase with the resetting rate. The effective efficiency that takes into account the work done due to resetting remains constant. However, if the work done due to resetting is ignored, then the system can incorrectly imply a different behaviour, including the false inference that it is not working as an engine at all. The efficient power is observed to increase beyond that obtained in the absence of resetting, and is shown to be higher for a three-level engine.

cond-mat.stat-mech↗

arXiv2022

Thermodynamics of one and two-qubit nonequilibrium heat engines running between squeezed thermal reservoirs

Quantum heat engines form an active field of research due to their potential applications. There are several phenomena that are unique to the quantum regime, some of which are known to give these engines an edge over their classical counterparts. In this work, we focus on the study of one and two-qubit finite-time Otto engines interacting with squeezed thermal baths, and discuss their important distinctions as well as the advantage of using the two-qubit engine. In particular, the two-qubit engine offers an interesting study of the interplay between the degree of squeezing and that of the coherence between the two qubits. We find that the two-qubit engine generally yields higher power than its one-qubit counterpart. The effective temperature of the squeezed baths can be calculated both for the one and two-qubit engines, and they tend to show an exponential growth with increase in squeezing parameters $r_h$ and $r_c$. It is also observed that by tuning the squeezing parameters, the machine can be made to work either in the engine or in the refrigerator mode. Additional effects due to the change in the inter-qubit separation have been studied.

cond-mat.stat-mech↗

arXiv2019

Storage of electrical energy: Batteries and Supercapacitors

In this article we shall discuss the development of electrical storage system. Since the early days of electricity people have tried various methods to store electricity. One of the earliest device was a simple electrostatic capacitor that could store less than a micro Joule of energy. The battery has been the most popular in storing electricity as it has a higher energy density. We will discuss the development of batteries and their working principle. Although capacitors has never been thought of as a practical device for electricity storage, in the recent years there has been tremendous progress in building capacitors with huge capacitance and it may soon be possible to use it as storage device. We shall discuss the technological breakthroug in supercapacitor as a storage device.

physics.app-ph↗

arXiv2018

Milling and meandering: Flocking dynamics of stochastically interacting agents with a field of view

We introduce a stochastic agent-based model for the flocking dynamics of self-propelled particles that exhibit velocity-alignment interactions with neighbours within their field of view. The stochasticity in the dynamics of the model arises purely from the uncertainties at the level of interactions. Despite the absence of attractive forces, this model gives rise to a wide array of emergent patterns that exhibit long-time spatial cohesion. In order to gain further insights into the dynamical nature of the resulting patterns, we investigate the system behaviour using an algorithm that identifies spatially distinct clusters of the flock and computes their corresponding angular momenta. Our results suggest that the choice of field of view is crucial in determining the resulting emergent dynamics of stochastically interacting particles.

cond-mat.stat-mech↗

arXiv2016

Jamming in a lattice model of stochastically interacting agents with a field of view

We study the collective dynamics of a lattice model of stochastically interacting agents with a weighted field of vision. We assume that agents preferentially interact with neighbours, depending on their relative location, through velocity alignments and the additional constraint of exclusion. Unlike in previous models of flocking, here the stochasticity arises intrinsically from the interactions between agents, and its strength is dependent on the local density of agents. We find that this system yields a first-order jamming transition as a consequence of these interactions, even at a very low density. Furthermore, the critical jamming density is found to strongly depend on the nature of the field of view.

cond-mat.stat-mech↗

arXiv2015

Synchronization in an evolving network

In this work we study the dynamics of Kuramoto oscillators on a stochastically evolving network whose evolution is governed by the phases of the individual oscillators and degree distribution. Synchronization is achieved after a threshold connection density is reached. This cumulative effect of topology and dynamics has many real-world implications, where synchronization in a system emerges as a collective property of its components in a self-organizing manner. The synchronous state remains stable as long as the connection density remains above the threshold value, with additional links providing resilience against network fluctuations.

physics.soc-ph↗

arXiv2015

Population extinction in an inhomogeneous host-pathogen model

We study inhomogeneous host-pathogen dynamics to model the global amphibian population extinction in a lake basin system. The lake basin system is modeled as quenched disorder. In this model we show that once the pathogen arrives at the lake basin it spreads from one lake to another, eventually spreading to the entire lake basin system in a wave like pattern. The extinction time has been found to depend on the steady state host population and pathogen growth rate. Linear estimate of the extinction time is computed. The steady state host population shows a threshold behavior in the interaction strength for a given growth rate.

q-bio.PE↗

arXiv2015

Kinetic Monte Carlo simulations of self organized nanostructures on Ta Surface Fabricated by Low Energy Ion Sputtering

Surfaces bombarded with low energy ion beams often display development of self assembled patterns and quasi-periodic structures. Kinetic Monte Carlo simulations have been performed to describe ion sputtered Tantalum surfaces. A weak nonlinearity in the relaxation process has been introduced and the results show that the Positive Schwoebel barrier, produced by the nonlinear Hamiltonian, is necessary in describing ion bombarded Tantalum surfaces. Furthermore, their scaling exponents suggest presence of a class other than KPZ.

cond-mat.mtrl-sci↗

arXiv2014

Trapping reaction in a symmetric double well potential

We study the trapping reaction-diffusion problem in a symmetric double well potential in one dimension with a static trap located at the middle of the central barrier of the double well. The effect of competition between the confinement and the trapping process on the time evolution of the survival probability is considered. The solution for the survival probability of a particle is obtained by the method of Green's function. Furthermore, we study trapping in the presence of a growth term. We show that for a given growth rate there exist a threshold trapping rate beyond which the population can become extinct asymptotically. Numerical simulations for a symmetric quartic potential are done and results are discussed. This model can be applied to study the dynamics of a population in habitats with a localized predation.

cond-mat.stat-mech↗

arXiv2013

Asymptotic survival probability of a particle in reaction-diffusion process with exclusion in the presence of traps

Reaction-diffusion process with exclusion in the presence of traps has been studied. The asymptotic survival probability for the case of uniformly distributed random traps shows a stretched e\ xponential behavior. We show that additional correction terms appear in the stretched exponent when exclusion is taken into account. Analytically it is shown to be $\sim t^{1/6}$ which is ver\ ified by numerical simulations.

cond-mat.stat-mech↗

arXiv2012

The effect of exclusion on nonlinear reaction diffusion system in inhomogeneous media

We study a minimal model to understand the formation of clusters on surfaces in the presence of surface defects. We consider reaction diffusion model in which atoms undergoes reactions at the defect centers to form clusters. Volume exclusion between particles is introduced through a drift term in the reaction diffusion equation that arises due the repulsive force field produced by the clustering atoms. The volume exclusion terms can be derived from master equation with a concentration dependent hopping rate. Perturbative analysis is performed for both cross-exclusion and self-exclusion one dimensional system. For two dimension numerical analysis is performed. We have found that the clusterization process slows down due to exclusion. As a result the size of the clusters reduces. In this model reaction scheme has algebraic nonlinearity and plausible mechanism is also given.

cond-mat.mtrl-sci↗

arXiv2012

Correlated Gaussian random walk models of animal dispersal

A correlated Gaussian random walk(CGRW) model is proposed as a simple model of animal dispersal. The general features of CGRW is described. We will discuss how from this single model a number of different kinds of correlated random walk can be studied. The CGRWs in one dimension is studied in detail and the special limiting cases are discussed where the probability densities are found analytically. Numerical simulations are performed and the results are found to be in good agreement with the theoretical predictions. Directional persistence in CGRWs is discussed for the one dimensional cases. We will show that correlation does not always give rise to directional persistence.

cond-mat.stat-mech↗