Showing papers by "Bidhan Chandra Bag published in 2021"
TL;DR: In this article, the Fokker-Planck equation (FPE) was used for the Brownian harmonic oscillator in the presence of a magnetic field and the non-Markovian thermal bath.
Abstract: In a recent paper Das et al. [J. Chem. Phys. 147, 164102 (2017)JCPSA60021-960610.1063/1.4999408] proposed the Fokker-Planck equation (FPE) for the Brownian harmonic oscillator in the presence of a magnetic field and the non-Markovian thermal bath, respectively. This system has been studied very recently by Hidalgo-Gonzalez and Jimenez-Aquino [Phys. Rev. E 100, 062102 (2019)PREHBM2470-004510.1103/PhysRevE.100.062102] and the Fokker-Planck equation was derived using the characteristic function. It includes a few extra terms in the FPE and the authors conclude that their method is accurate compared to the calculation by Das et al. Then we reexamine our calculation and which is present in this comment. The revised calculation shows that both methods give the same result.
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TL;DR: In this paper, the authors investigated the dynamics of a damped harmonic oscillator in the presence of an electromagnetic field and found that the magnetic field may induce an asymmetric splitting of the spectrum of the output signal with two peaks in the case of a driven damped two-dimensional harmonic oscillators.
Abstract: In this paper we have investigated the dynamics of a damped harmonic oscillator in the presence of an electromagnetic field. The transients for the two dimensional harmonic oscillator imply about the modulation of the frequency of the oscillator by the velocity dependent non conservative force from an applied magnetic field. Except a special condition, the motion is in general quasi periodic nature even in the absence of damping. Another interesting finding is that the magnetic field may induce an asymmetric splitting of the spectrum of the output signal with two peaks in the case of a driven damped two dimensional harmonic oscillator. One more additional peak may appear for the three dimensional case. In some cases the spectrum may have similarity with the Normal Zeeman Effect. At the same time one may observe to appear the anti resonance phenomenon even for the driven damped cyclotron motion where the system with the purely non conservative force fields is driven by an electric field. Finally, our calculation exhibits how the magnetic field can modulate the phase difference (between input and output signals) and the efficiency like quantity of the energy storing process. Thus the present study might be applicable in the areas related to the refractive index, the barrier crossing dynamics and autonomous stochastic resonance, respectively.
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TL;DR: In this article, the authors presented the mechanism of the barrier crossing dynamics of a Brownian particle coupled to a thermal bath in the presence of both time independent and fluctuating magnetic fields.
Abstract: In this paper we have presented the mechanism of the barrier crossing dynamics of a Brownian particle which is coupled to a thermal bath in the presence of both time independent and fluctuating magnetic fields. Here the following three aspects are important in addition to the role of the thermal bath on the barrier crossing dynamics. Magnetic field induced coupling may introduce a resonance like effect. Another role of the field is that enhancement of its strength reduces the frequency factor of the barrier crossing rate constant. Finally, the fluctuating magnetic field introduces an induced electric field which activates the Brownian particle to cross the energy barrier. As a result of interplay among these aspects versatile non-monotonic behavior may appear in the variation of the rate constant as a function of the strength of the time independent magnetic field.
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TL;DR: In this article, it was shown that the noise induced transition phenomenon may be observed even in a linear stochastic process where both deterministic and non-deterministic parts are linear functions of the relevant phase space variables.
Abstract: It seems to us that a stochastic system must be a nonlinear one to observe the phenomenon, noise induced transition. But in the present paper, we have demonstrated that the phenomenon may be observed even in a linear stochastic process where both deterministic and stochastic parts are linear functions of the relevant phase space variables. The shape of the stationary distribution of particles (which are confined in a harmonic potential) may change on increasing the strength of the applied fluctuating magnetic field. The probability density may vary non monotonically with an increase in the coordinate of a Brownian particle. Thus the distribution of particles may deviate strongly from the Boltzmann one and it is a unique signature of the fluctuating magnetic field. Then we are motivated strongly to study the distribution of particles in a nonlinear stochastic system where the Brownian particles are confined in a bi-stable potential energy field in the presence of the fluctuating magnetic field. With a relatively large strength of the fluctuating field, the distribution of particles may be a strange one where many islands may appear which are not expected from the given potential energy field. It may offer an explanation to describe the phenomenon, the reduction of the current in a semiconductor in the presence of a time dependent magnetic field.