Hetampur Raj High School

Birbhum, India

Hetampur Raj High School

Birbhum, India
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Datta N.K.,Suri Vidyasagar College | Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Chemical Physics | Year: 2012

We investigate the excitation behavior of a repulsive impurity doped quantum dot under the combined influence of oscillatory confinement potential and oscillatory magnetic field. In view of this the ratio of two oscillation frequencies has been exploited meticulously. We have considered Gaussian impurity centers. The investigation reveals that a variation in the aforesaid frequency ratio causes maximization in the time-average excitation rate for different dopant locations. To make the analysis more realistic and rational, concomitant oscillation in the spatial stretch of the dopant is also considered in a stepwise manner. Although the consideration makes the calculation much more tedious and involved, yet this adequately describes the role played by the undulating impurity domain exclusively in modulating the excitation rate. © 2012 Elsevier B.V. All rights reserved.


Pal S.,Hetampur Raj High School | Datta N.K.,Suri Vidyasagar College | Ghosh M.,Visva Bharati University
Journal of Physical Chemistry C | Year: 2013

Excitation in quantum dots is a hotly pursued phenomenon. Realizing it, we investigate the excitation kinetics of a repulsive impurity doped quantum dot as the dopant is propagating. Such a propagation is assumed to be important because of its close connection with impurity drift in nanodevices. The problem has been made more realistic by considering the dopant propagation to be damped. For simplicity, we have considered an inherently linear propagation of the dopant, and the impurity potential has been assumed to have a Gaussian nature. The damping strength and the initial spatial stretch of the dopant have been found to fabricate the said kinetics in a delicate way. However, in the overdamped region, we find attainment of stabilization in the excitation rate invariably. Determination of average accelerating force imparted onto the propagating dopant seems to consolidate the findings. The present investigation is believed to provide some useful insight into the phenomenon of damping that has potential importance in nanoelectronic applications. © 2013 American Chemical Society.


Pal S.,Hetampur Raj High School | Sinha S.S.,Jackson State University | Ganguly J.,Brahmankhanda Basapara High School | Ghosh M.,Visva Bharati University
Chemical Physics | Year: 2013

We investigate the excitation kinetics of a repulsive impurity doped quantum dot initiated by simultaneous application of Gaussian white noise and external sinusoidal field. We have considered both additive and multiplicative noise (in Stratonovich sense). The combined influences of noise strength (ζ) and the field intensity (ε) have been capsuled by invoking their ratio (η). The said ratio and the dopant location have been found to fabricate the kinetics in a delicate way. Moreover, the influences of additive and multiplicative nature of the noise on the excitation kinetics have been observed to be widely different. The investigation reveals emergence of maximization/minimization and saturation in the excitation kinetics as a result of complex interplay between η and the dopant coordinate (r0). The present investigation is believed to provide some useful insights in the functioning of mesoscopic devices where noise plays some significant role. © 2013 Elsevier B.V. All rights reserved.


Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Superlattices and Microstructures | Year: 2014

We investigate the profiles of diagonal components of frequency-dependent linear (αxx and αyy), and first nonlinear (βxxx and βyyy) optical response of repulsive impurity doped quantum dots. The dopant impurity potential chosen assumes Gaussian form. The study principally focuses on investigating the role of damping on the polarizability components. In view of this the dopant is considered to be propagating under damped condition which is otherwise linear inherently. The frequency-dependent polarizabilities are then analyzed by placing the doped dot to a periodically oscillating external electric field of given intensity. The damping strength, in conjunction with external oscillation frequency and confinement potentials, fabricate the polarizability components in a fascinating manner which is adorned with emergence of maximization, minimization, and saturation. The discrimination in the values of the polarizability components in x and y-directions has also been addressed in the present context. © 2014 Elsevier Ltd. All rights reserved.


Ganguly J.,Brahmankhanda Basapara High School | Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Superlattices and Microstructures | Year: 2013

We investigate the excitation kinetics of a repulsive impurity doped quantum dot initiated by the application of additive Gaussian white noise. The noise and the dot confinement sources of electric and magnetic origin have been found to fabricate the said kinetics in a delicate way. In addition to this the dopant location also plays some prominent role. The present study sheds light on how the individual or combined variation of different confinement sources could design the excitation kinetics in presence of noise. The investigation reveals emergence of maximization and saturation in the excitation kinetics as a result of complex interplay between various parameters that affect the kinetics. The phase space plots are often invoked and they lend credence to the findings. The present investigation is believed to provide some useful perceptions of the functioning of mesoscopic systems where noise plays some profound role. © 2013 Elsevier Ltd. All rights reserved.


Ganguly J.,Brahmankhanda Basapara High School | Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Superlattices and Microstructures | Year: 2013

We investigate the excitation kinetics of a repulsive impurity doped quantum dot initiated by the application of multiplicative Gaussian white noise. The noise strength and the dot confinement sources of electric and magnetic origin have been found to produce the said kinetics in a subtle way. In addition to this the dopant location also plays some crucial role. The present study sheds light on how the individual or combined variation of different confinement sources could design the excitation kinetics in presence of noise. The investigation reveals maximization and saturation in the excitation kinetics as a result of complex interplay between the confinement potentials of the dot, the dopant location, and the noise strength. The present investigation is believed to provide some useful perceptions of the functioning of mesoscopic systems where noise plays some profound role.© 2013 Elsevier Ltd. All rights reserved.


Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Journal of Luminescence | Year: 2013

Excitation in quantum dots is an important phenomenon. Realizing the importance we investigate the excitation behavior of a repulsive impurity doped quantum dot induced by an external oscillatory field. As an obvious consequence the simultaneous oscillation of spatial stretch of impurity domain has also been taken into account. The impurity potential has been assumed to have a Gaussian nature. The ratio of two oscillations (η) has been exploited to understand the nature of excitation. Indeed it has been found that the said ratio could orchestrate the excitation in a truly elegant way. Apart from the ratio, the dopant location also plays some meaningful role towards modulating the excitation rate. The present study also indicates the attainment of stabilization in the excitation rate as soon as η surpasses a threshold value irrespective of the dopant location. Moreover, prior to the onset of stabilization we also envisage minimization in the excitation rate at some typical η values depending on the dopant location. The critical analysis of pertinent impurity parameters provides important perception about the physics behind the excitation process. © 2013 Elsevier B.V.


Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Chemical Physics Letters | Year: 2014

We investigate the profiles of diagonal components of static and frequency-dependent third nonlinear (γxxxx and γyyyy) polarizability of repulsive impurity doped quantum dots. The dopant impurity potential takes a Gaussian form. We have considered propagation of the dopant within an environment that damps the motion. The study focuses on role of damping strength on the diagonal components of both static and frequency-dependent third nonlinear polarizability of the doped system. The doped system is further exposed to an external electric field of given intensity. Damping subtly modulates the dot-impurity interaction and fabricates the polarizability components in a noticeable manner. © 2014 Elsevier B.V. All rights reserved.


Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Chemical Physics | Year: 2013

We investigate the excitation kinetics of a repulsive impurity doped quantum dot as the dopant is propagating. The study assumes importance because of its intimate connection with impurity drift in nanode- vices. The problem has been made more realistic by considering the dopant propagation to be damped. For simplicity, we have considered an inherently linear motion of the dopant with a Gaussian potential. The damping strength and the dot confinement sources of electric and magnetic origin have been found to fabricate the said kinetics in a delicate way. The present study sheds light on how the individual or combined variation of different confinement sources could design the excitation kinetics in presence of damping. However, in the overdamped region, we find attainment of stabilization in the excitation rate. The present investigation is believed to provide some useful perceptions in the phenomenon of damping that has potential importance in nanoelectronic applications. © 2013 Elsevier B.V. All rights reserved.


Pal S.,Hetampur Raj High School | Ghosh M.,Visva Bharati University
Superlattices and Microstructures | Year: 2013

Excitation in quantum dots is an important phenomenon. Realizing the importance we explore the excitation kinetics of a repulsive impurity doped quantum dot induced by an electromagnetic pulsed field of various pulse shapes. The pulsed field has been applied along both x and y directions to the doped quantum dot. The impurity potential has been assumed to have a Gaussian nature. The investigation reveals the sensitivity of the typical shape of the pulse, alongside the influences of dopant location and number of pulse towards modulating the excitation rate. At first we have concentrated on understanding the role of number of pulses fed into the system on the kinetics at three fixed dopant locations. Next, we have given our thrust in analyzing the exclusive role of dopant location on excitation kinetics at a fixed pulsed number. In both the cases the typical pulse shapes announce its role on excitation kinetics unhesitatingly through a number of observations. The present study has also indicated enough evidence of change in the mutual dominance of several factors that could favor and impede excitation accompanying the shift of dopant location. Importantly, those factors also depend severely on the pulse shape. The pulse shape interferes delicately with the interplay between impurity location and number of pulses fed into the system and emerges as an important ingredient that can engineer the excitation kinetics. © 2012 Elsevier Ltd. All rights reserved.

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