Group Theoretical Description of the Periodic System

The group theoretical description of the periodic system of elements in the framework of the Rumer–Fet model is considered. We introduce the concept of a single quantum system, the generating core of which is an abstract C*-algebra. It is shown that various concrete implementations of the operator algebra depend on the structure of the generators of the fundamental symmetry group attached to the energy operator. In the case of the generators of the complex shell of a group algebra of a conformal group, the spectrum of states of a single quantum system is given in the framework of the basic representation of the Rumer–Fet group, which leads to a group-theoretic interpretation of the Mendeleev’s periodic system of elements. A mass formula is introduced that allows giving the termwise mass splitting for the main multiplet of the Rumer–Fet group. The masses of elements of the Seaborg table (eight-periodic extension of the Mendeleev table) are calculated starting from the atomic number Z=3 and going to Z=220. The continuation of the Seaborg homology between lanthanides and actinides is established with the group of superactinides. A 10-periodic extension of the periodic table is introduced in the framework of the group-theoretic approach. The multiplet structure of the extended table’s periods is considered in detail. It is shown that the period lengths of the system of elements are determined by the structure of the basic representation of the Rumer–Fet group. The theoretical masses of the elements of 10th and 11th periods are calculated starting from Z=221 and going to to Z=364. The concept of hypertwistor is introduced.

Single-photon emission and multi-photon emission from single CdTeSe/ZnS quantum dots at room temperature

In this report, single-photon emission and ordered multi-photon emission from single colloidal CdTeSe/ZnS quantum dots at near-infrared wavelength were realized at room temperature. The fluorescence lifetime, blinking, and anti-bunching effect of this single quantum dots at different excitation powers were measured. The relationship between the excitation power and the emission of exciton, biexciton and multiexciton of single quantum dots at a wavelength of 800nm was obtained. The physical mechanism of photoluminescence of the single quantum dots was analyzed.

A Bayesian Network-based Quantum procedure for Failure Risk Analysis

<div> <div> <div> <p>Studying the propagation of failure probabilities in interconnected systems like that of electrical distribution networks is traditionally performed by means of Monte Carlo simulations. In this paper, we propose a procedure to create a model of the system in a quantum computer using a restricted representation of Bayesian networks. Some examples of this implementation on sample models are presented using Qiskit and tested using both quantum simulators and IBM Quantum hardware. Results show a correlation in the precision of the results when considering the number of Monte Carlo iterations alongside the sum of shots in a single quantum circuit execution. </p> </div> </div> </div>

A Bayesian Network-based Quantum procedure for Failure Risk Analysis

<div> <div> <div> <p>Studying the propagation of failure probabilities in interconnected systems like that of electrical distribution networks is traditionally performed by means of Monte Carlo simulations. In this paper, we propose a procedure to create a model of the system in a quantum computer using a restricted representation of Bayesian networks. Some examples of this implementation on sample models are presented using Qiskit and tested using both quantum simulators and IBM Quantum hardware. Results show a correlation in the precision of the results when considering the number of Monte Carlo iterations alongside the sum of shots in a single quantum circuit execution. </p> </div> </div> </div>

Stacked metasurfaces for enhancing the emission and extraction rate of single nitrogen-vacancy centers in nanodiamond

Dielectric metasurfaces with unique possibilities of manipulating light-matter interaction lead to new insights in exploring spontaneous emission control using single quantum emitters. Here, we study the stacked metasurfaces in one- (1D) and two-dimensions (2D) to enhance the emission rate of a single quantum emitter using the associated optical resonances. The 1D structures with stacked bilayers are investigated to exhibit Tamm plasmon resonance optimized at the zero phonon line (ZPL) of the negative nitrogen-vacancy (NV-) center. The 2D stacked metasurface comprising of two-slots silicon nano-disks is studied for the Kerker condition at ZPL wavelength. The far-field radiation plots for the 1D and 2D stacked metasurfaces show an increased extraction efficiency rate for the NV- center at ZPL wavelength that reciprocates the localized electric field intensity. The modified local density of optical states results in large Purcell enhancement of 3.8 times and 25 times for the single NV- center integrated with 1D and 2D stacked metasurface, respectively. These results have implications in exploring stacked metasurfaces for applications such as single photon generation and CMOS compatible light sources for on-demand chip integration.

Modeling and Simulations of 4H-SiC/6H-SiC/4H-SiC Single Quantum-Well Light Emitting Diode Using Diffusion Bonding Technique

In the last decade, Silicon carbide (SiC) has emerged as a potential material for high-frequency electronics and optoelectronics applications that may require elevated temperature processing. SiC exists in more than 200 different crystallographic forms, referred to as polytypes. Based on their remarkable physical and electrical characteristics, such as better thermal and electrical conductivities, 3C-SiC, 4H-SiC, and 6H-SiC are considered as the most distinguished polytypes of SiC. In this article, physical device simulation of a light-emitting diode (LED) based on the unique structural configuration of 4H-SiC and 6H-SiC layers has been performed which corresponds to a novel material joining technique, called diffusion welding/bonding. The proposed single quantum well (SQW) edge-emitting SiC-based LED has been simulated using a commercially available semiconductor device simulator, SILVACO TCAD. Moreover, by varying different design parameters, the current-voltage characteristics, luminous power, and power spectral density have been calculated. Our proposed LED device exhibited promising results in terms of luminous power efficiency and external quantum efficiency (EQE). The device numerically achieved a luminous efficiency of 25% and EQE of 16.43%, which is at par performance for a SQW LED. The resultant LED structure can be customized by choosing appropriate materials of varying bandgaps to extract the light emission spectrum in the desired wavelength range. It is anticipated that the physical fabrication of our proposed LED by direct bonding of SiC-SiC wafers will pave the way for the future development of efficient and cost-effective SiC-based LEDs.