arXiv subjects

Parthapratim Biswas

Publications and source records attributed to Parthapratim Biswas.

42 records · Page 3Linked to original sources

arXiv1999

Electron delocalization and multifractal scaling in electrified random chains

Electron localization property of a random chain changing under the influence of a constant electric field has been studied. We have adopted the multifractal scaling formalism to explore the possible localization behavior in the system. We observe that the possible localization behavior with the increase of electric field is not systematic and shows strong instabilities associated with the local probability variation over the length of the chain. The multifractal scaling study captures the localization aspects along with strong instability when the electric field is changed by infinitesimal steps for a reasonably large system size.

cond-mat.dis-nn↗

arXiv1999

An augmented space recursion study of the electronic structure of rough epitaxial overlayers

In this communication we propose the use of the Augmented Space Recursion as an ideal methodology for the study of electronic and magnetic structures of rough surfaces, interfaces and overlayers. The method can take into account roughness, short-ranged clustering effects, surface dilatation and interdiffusion. We illustrate our method by an application of Fe overlayer on Ag (100) surface.

cond-mat.mtrl-sci↗

arXiv1998

Multifractal scaling of electronic transmission resonances in perfect and imperfect Fibonacci $δ$-function potentials

We present here a detailed multifractal scaling study for the electronic transmission resonances with the system size for an infinitely large one dimensional perfect and imperfect quasiperiodic system represented by a sequence of $δ$-function potentials. The electronic transmission resonances in the energy minibands manifest more and more fragmented nature of the transmittance with the change of system sizes. We claim that when a small perturbation is randomly present at a few number of sites, the nature of electronic states will change and this can be understood by studying the electronic transmittance with the change of system size. We report the different critical states manifested in the size variation of the transmittance corresponding to the resonant energies for both perfect and imperfect cases through multifractal scaling study for few of these resonances.

cond-mat↗

arXiv1997

Smoothing of sandpile surfaces after intermittent and continuous avalanches: three models in search of an experiment

We present and analyse in this paper three models of coupled continuum equations all united by a common theme: the intuitive notion that sandpile surfaces are left smoother by the propagation of avalanches across them. Two of these concern smoothing at the `bare' interface, appropriate to intermittent avalanche flow, while one of them models smoothing at the effective surface defined by a cloud of flowing grains across the `bare' interface, which is appropriate to the regime where avalanches flow continuously across the sandpile.

cond-mat.soft↗

arXiv1997

Some properties of a class of coupled Langevin equations

We present a set of coupled continuum equationswith a specific coupling between mobile grains $ρ$ and clusters $h$ on the surface of a sandpile. The equations are analysed self-consistently; we demonstrate that Edwards' infrared divergence is responsible for the unexpected critical exponents we find, which are verified by simulations.

cond-mat.stat-mech↗

arXiv1997

In search of smooth sandpiles: the Edwards-Wilkinson equation with flow

The well-known Edwards-Wilkinson equation with a flow term added exhibits a smoothing fixed point in addition to the normal EW fixed point. Based on this, we present a model of sandpiles involving a coupling between fixed and mobile grains, which then shows the smoothing behaviour that would be expected to obtain after avalanche propagation.

cond-mat.dis-nn↗