Prabir Kumar Haldar

Bio: Prabir Kumar Haldar is an academic researcher from Cooch Behar Panchanan Barma University. The author has contributed to research in topics: Factorial moment & Multifractal system. The author has an hindex of 8, co-authored 48 publications receiving 225 citations. Previous affiliations of Prabir Kumar Haldar include Jadavpur University & Rishi Bankim Chandra Colleges.

Nonvolatile resistive switching and synaptic characteristics of lead-free all-inorganic perovskite-based flexible memristive devices for neuromorphic systems

Abstract: Recently, several types of lead halide perovskites have been actively researched for resistive switching (RS) memory or artificial synaptic devices due to their current–voltage hysteresis along with the feasibility of fabrication, low-temperature processability and superior charge mobility. However, the toxicity and environmental pollution potential of lead halide perovskites severely restrict their large-scale commercial prospects. In the present work, the environmentally friendly and uniform CsSnCl3 perovskite films are introduced to act as an active layer in the flexible memristors. Ag/CsSnCl3/ITO devices demonstrate bipolar RS with excellent electrical properties such as forming free characteristics, good uniformity, low operating voltages, a high ON/OFF ratio (102) and a long retention time (>104 s). The RS mechanism has been well explained in the outline of electric field-induced formation and rupture of Ag filaments in the CsSnCl3 layer. The metallic nature of the conducting filament has been further confirmed by temperature-dependent variation of low and high resistance states. Additionally, various pulse measurements have been carried out to mimic some of the basic synaptic functions including postsynaptic current, paired-pulse facilitation, long-term potentiation and long-term depression under normal as well as bending conditions. Our work provides the opportunity for exploring artificial synapses based on lead-free halide perovskites for the development of next-generation flexible electronics.

Multifractal analysis of multiparticle emission data in the framework of visibility graph and sandbox algorithm

Abstract: Multiparticle emission data in nucleus–nucleus collisions are studied in a graph theoretical approach. The sandbox algorithm used to analyze complex networks is employed to characterize the multifractal properties of the visibility graphs associated with the pseudorapidity distribution of charged particles produced in high-energy heavy-ion collisions. Experimental data on 28Si+Ag/Br interaction at laboratory energy E lab = 14 . 5 A GeV, and 16O+Ag/Br and 32S+Ag/Br interactions both at E lab = 200 A GeV, are used in this analysis. We observe a scale free nature of the degree distributions of the visibility and horizontal visibility graphs associated with the event-wise pseudorapidity distributions. Equivalent event samples simulated by ultra-relativistic quantum molecular dynamics, produce degree distributions that are almost identical to the respective experiment. However, the multifractal variables obtained by using sandbox algorithm for the experiment to some extent differ from the respective simulated results.

Enhancement of data storage capability in a bilayer oxide-based memristor for wearable electronic applications

Abstract: In this work, a ZnO/NiO bilayer architecture is introduced to fabricate transparent and flexible resistive random access memory (RRAM) device (Cu/ZnO/NiO/ITO) on polyethylene terephthalate (PET) substrate. The device exhibits excellent RS characteristics, such as forming free characteristic, low operating voltages, outstanding uniformity, long retention time (>104 s), high ON/OFF current ratio ~103, reliable multilevel cell (MLC) characteristics and excellent mechanical flexibility. The multilevel properties has been systematically evaluated by varying the compliance current and by tuning the stopping voltage, which shows that all the resistance state are distinguishable and remained stable without any considerable deprivation over 103 s. Intrinsic tailoring of RS mechanism has been well explained in the framework of electric field-induced formation and rupture of the reproducible Cu filaments in ZnO/NiO layer. Further, the metallic nature of conducting filament has further been confirmed by temperature-dependent variation of the high and low resistance states. Owing to the increasing demand of flexible electronics, the mechanical robustness of the proposed device has been examined by varying bending time and radius. The present RS device shows potential toward integration in many transparent, flexible and high-density storage devices, such as electronic skins and flexible displays.

Evidence of fractal behavior of pions and protons in high energy interactions — an experimental investigation

Abstract: Different fractal methods (Factorial moment, Takagi moment) have been used for the analysis of fractal behavior of multiparticle production in π--AgBr interaction at 350 GeV/c of compound multiplicity distribution in emission angle (cos θ) space and azimuthal angle (ϕ) space. The generalized fractal dimensions Dq are determined according to two methods. Results indicate multifractal behavior in compound multiplicity distribution. From the knowledge of Dq, the multifractal specific heat is calculated. Results are compared with the corresponding results of shower multiplicity.

Validity of the negative binomial multiplicity distribution in case of ultra-relativistic nucleus-nucleus interaction in different azimuthal bins

Abstract: This work studies the validity of the negative binomial distribution in the multiplicity distribution of charged secondaries in 16O and 32S interactions with AgBr at 60 GeV/c per nucleon and 200 GeV/c per nucleon, respectively. The validity of negative binomial distribution (NBD) is studied in different azimuthal phase spaces. It is observed that the data can be well parameterized in terms of the NBD law for different azimuthal phase spaces.

Introduction to High-Energy Heavy-Ion Collisions

Abstract: The author has succeeded in writing a well-balanced textbook of the new field of ultra-relativistic heavy-ion collisions (RHICs). The book is primarily suited to theoretically oriented graduate students and researchers (both theorists and experimental physicists). After introducing the necessary kinematical variables and describing the phenomenology of nucleon--nucleon collisions, the author proceeds to elucidate various concepts of high-energy particle physics which are relevant to the study of RHICs. Among these are the hard-scattering model, the Schwinger particle production mechanism, the classical string model and the dual parton model. He then focuses on the concept of the quark--gluon plasma (QGP) and gives an overview of the methods and results of lattice gauge theory. The final chapters of the book are devoted to the creation of a QGP via heavy-ion collisions and its possible signatures. In great detail the author discusses dilepton production, suppression, photon production, Hanbury--Brown--Twiss interferometry and strangeness enhancement. The book is very well written and I can recommend it to all graduate students and researchers interested in the field of RHICs. However, the book has one shortcoming: it focuses on heavy-ion physics in the energy region E > 200 GeV/nucleon and higher. The physics of the hadron gas, important for the later stages of RHICs at CERN and dominant for beam energies in the BEVALAC/SIS/AGS range, is neglected. To acquire an overview of the entire field of RHICs, the reader would profit from a supplementary reading of the more introductory textbook Introduction to Relativistic Heavy-Ion Collisions by L Csernai.

Measure representation and multifractal analysis of complete genomes

Abstract: This paper introduces the notion of measure representation of DNA sequences. Spectral analysis and multifractal analysis are then performed on the measure representations of a large number of complete genomes. The main aim of this paper is to discuss the multifractal property of the measure representation and the classification of bacteria. From the measure representations and the values of the Dq spectra and related Cq curves, it is concluded that these complete genomes are not random sequences. In fact, spectral analyses performed indicate that these measure representations, considered as time series, exhibit strong long-range correlation. Here the long-range correlation is for the K-strings with dictionary ordering, and it is different from the base pair correlations introduced by other people. For substrings with length K=8, the Dq spectra of all organisms studied are multifractal-like and sufficiently smooth for the Cq curves to be meaningful. With the decreasing value of K, the multifractality lessens. The Cq curves of all bacteria resemble a classical phase transition at a critical point. But the ‘‘analogous’’ phase transitions of chromosomes of nonbacteria organisms are different. Apart from chromosome 1 of C. elegans, they exhibit the shape of double-peaked specific heat function. A classification of genomes of bacteria by assigning to each sequence a point in two-dimensional space (D_{-1} ,D1) and in three-dimensional space (D_{-1} ,D1 ,D_{-2}) was given. Bacteria that are close phylogenetically are almost close in the spaces (D_{-1} ,D1) and (D_{-1} ,D1 ,D_{-2}).

Nanostructured perovskites for nonvolatile memory devices.

Abstract: Perovskite materials have driven tremendous advances in constructing electronic devices owing to their low cost, facile synthesis, outstanding electric and optoelectronic properties, flexible dimensionality engineering, and so on. Particularly, emerging nonvolatile memory devices (eNVMs) based on perovskites give birth to numerous traditional paradigm terminators in the fields of storage and computation. Despite significant exploration efforts being devoted to perovskite-based high-density storage and neuromorphic electronic devices, research studies on materials' dimensionality that has dominant effects on perovskite electronics' performances are paid little attention; therefore, a review from the point of view of structural morphologies of perovskites is essential for constructing perovskite-based devices. Here, recent advances of perovskite-based eNVMs (memristors and field-effect-transistors) are reviewed in terms of the dimensionality of perovskite materials and their potentialities in storage or neuromorphic computing. The corresponding material preparation methods, device structures, working mechanisms, and unique features are showcased and evaluated in detail. Furthermore, a broad spectrum of advanced technologies (e.g., hardware-based neural networks, in-sensor computing, logic operation, physical unclonable functions, and true random number generator), which are successfully achieved for perovskite-based electronics, are investigated. It is obvious that this review will provide benchmarks for designing high-quality perovskite-based electronics for application in storage, neuromorphic computing, artificial intelligence, information security, etc.