Amita Asthana^1,*, Anil Kumar¹, Preeta Sharan²

Computer Systems Science and Engineering, Vol.45, No.3, pp. 2901-2917, 2023, DOI:10.32604/csse.2023.030548

Abstract Quantum dot cellular automata (QCA) technology is emerging as a future technology which designs the digital circuits at quantum levels. The technology has gained popularity in terms of designing digital circuits, which occupy very less area and less power dissipation in comparison to the present complementary metal oxide semiconductor (CMOS) technology. For designing the routers at quantum levels with non-blocking capabilities various multi-stage networks have been proposed. This manuscript presents the design of the N×N Clos switch matrix as a multistage interconnecting network using quantum-dot cellular automata technology. The design of the Clos switch matrix presented in the article uses… More >

Sung Won Hwang, Dae-Ki Hong^*

CMC-Computers, Materials & Continua, Vol.74, No.1, pp. 55-66, 2023, DOI:10.32604/cmc.2023.028845

Abstract The use a stabilized lithium structure as cathode material for batteries could be a fundamental alternative in the development of next-generation energy storage devices. However, the lithium structure severely limits battery life causes safety concerns due to the growth of lithium (Li) dendrites during rapid charge/discharge cycles. Solid electrolytes, which are used in high-density energy storage devices and avoid the instability of liquid electrolytes, can be a promising alternative for next-generation batteries. Nevertheless, poor lithium ion conductivity and structural defects at room temperature have been pointed out as limitations. In this study, through the application of a low-dimensional graphene quantum… More >

Sung Won Hwang, Dae-Ki Hong^*

CMC-Computers, Materials & Continua, Vol.72, No.2, pp. 3283-3297, 2022, DOI:10.32604/cmc.2022.025931

Abstract Artificial neural networks (ANNs) are attracting attention for their high performance in various fields, because increasing the network size improves its functioning. Since large-scale neural networks are difficult to implement on custom hardware, a two-dimensional (2D) structure is applied to an ANN in the form of a crossbar. We demonstrate a synapse crossbar device from recent research by applying a memristive system to neuromorphic chips. The system is designed using two-dimensional structures, graphene quantum dots (GQDs) and graphene oxide (GO). Raman spectrum analysis results indicate a D-band of 1421 cm⁻¹ that occurs in the disorder; band is expressed as an atomic… More >

Miroslav Repka^1,*, Jan Sladek¹, Vladimir Sladek¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 10-10, 2021, DOI:10.32604/icces.2021.08308

Abstract The flexoelectric effect is investigated in quantum dot (QD) nano-sized structures. The lattice mismatch between QD and matrix results in non-uniform strains and presence of the strain gradients in the structure. The strain gradients induces the change of the polarization in QD structure as a consequence of the flexoelectric effect. When the dimensions of the QDs are of the same order of magnitude as the material length scale, gradient elasticity theory should be used to account for the size dependent of such nano-sized QDs. In this work the flexoelectric theory is applied for 3D analysis of QDs with the functionally… More >

E. K. Moioli¹, B. Shah¹, P. A. Clark¹, M. Stroscio¹, J. J. Mao¹

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 153-155, 2006, DOI:10.32604/mcb.2006.003.153

Abstract This article has no abstract. More >

Shyamalima Sharma, Pronob Gogoi, Bhaskar Jyoti Saikia, Swapan K. Dolui^*

Journal of Renewable Materials, Vol.4, No.2, pp. 158-162, 2016, DOI:10.7569/JRM.2015.634116

Abstract Cadmium sulfi de (CdS) quantum dots (QDs) were synthesized by a standard hydrothermal method with simultaneous desulfurization of kerosene oil. Sulfur containing kerosene oil was treated with cadmium chloride (CdCl2) in the presence of sodium hydroxide (NaOH) at 120 °C for 1.5 to 5 h. CdS was formed and sulfur content of oil gradually decreased. Thus, desulfurization of the oil occurred with the formation of the CdS QDs. The concentration of sulfur decreased to a minimum of 0.055% after 5 h of the reaction. In addition, the particle size of QDs increased from 5.4 nm to 8.1 nm as the… More >

Gerhard Klimeck^1,2, Fabiano Oyafuso², Timothy B. Boykin³, R. Chris Bowen², Paul von Allmen⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.5, pp. 601-642, 2002, DOI:10.3970/cmes.2002.003.601

Abstract Material layers with a thickness of a few nanometers are common-place in today's semiconductor devices. Before long, device fabrication methods will reach a point at which the other two device dimensions are scaled down to few tens of nanometers. The total atom count in such deca-nano devices is reduced to a few million. Only a small finite number of "free'' electrons will operate such nano-scale devices due to quantized electron energies and electron charge. This work demonstrates that the simulation of electronic structure and electron transport on these length scales must not only be fundamentally quantum mechanical, but it must… More >

Che-Wun Hong^1,2, Wei-Hui Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.3, pp. 211-228, 2011, DOI:10.3970/cmes.2011.072.211

Abstract This paper intends to use semiconductor quantum dots (cadmium sulphide- CdS) and/or biological pigments (chlorophyll-a derivatives) to replace those expensive ruthenium (Ru) dyes in photoelectrochemical solar cells. Based on the computational quantum chemistry, the molecular structures of (CdS)_n (n=1 ~ 22) clusters and chlorophyll-a derivatives (chlorin-H₃⁺ and chlorin-H₁₇⁺) are configured and optimized. Density functional theory (DFT) of the first principles calculations, which chose B3LYP (Becke 3-parameter Lee-Yang-Parr) and PBE (Perdew-Burke- Ernzerhof) exchange correlation functionals, is employed. Photoelectric properties, such as: molecular orbital, density of state (DOS), highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and resultant band gaps… More >

E. Pan^1,2, Y. Zhang², P. W. Chung³, M. Denda⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 157-168, 2008, DOI:10.3970/cmes.2008.024.157

Abstract Quantum-dot (QD) semiconductor synthesis is one of the most actively investigated fields in strain energy band engineering. The induced strain fields influence ordering and alignment, and the subsequent surface formations determine the energy bandgap of the device. The effect of the strains on the surface formations is computationally expensive to simulate, thus analytical solutions to the QD-induced strain fields are very appealing and useful. In this paper we present an analytical method for calculating the QD-induced elastic field in anisotropic half-space semiconductor substrates. The QD is assumed to be of any polyhedral shape, and its surface is approximated efficiently by… More >

Philippe Matagne¹, Jean-Pierre Leburton², Jacques Destine, Guy Cantraine³

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 1-10, 2000, DOI:10.3970/cmes.2000.001.001

Abstract We investigate the quantum mechanical properties and single-electron charging effects in vertical semiconductor quantum dots by solving the Schrödinger and Poisson (SP) equations, self-consistently. We use the finite element method (FEM), specifically the Bubnov-Galerkin technique to discretize the SP equations. Owing to the cylindrical symmetry of the structure, the mesh is generated from hexahedral volume elements. The fine details of the electron spectrum and wavefunctions in the quantum dot are obtained as a function of macroscopic parameters such as the gate voltage, device geometry and doping level. The simulations provide comprehensive data for the analysis of the experimental data of… More >