With prevalent attacks in communication, sharing a secret between communicating parties is an ongoing challenge. Moreover, it is important to integrate quantum solutions with classical secret sharing schemes with low computational cost for the real world use. This paper proposes a novel hybrid threshold adaptable quantum secret sharing scheme, using an m-bonacci orbital angular momentum (OAM) pump, Lagrange interpolation polynomials, and reverse Huffman-Fibonacci-tree coding. To be exact, we employ entangled states prepared by m -bonacci sequences to detect eavesdropping. Meanwhile, we encode m -bonacci sequences in Lagrange interpolation polynomials to generate the shares of a secret with reverse Huffman-Fibonacci-tree coding. The advantages of the proposed scheme is that it can detect eavesdropping without joint quantum operations, and permits secret sharing for an arbitrary but no less than threshold-value number of classical participants with much lower bandwidth. Also, in comparison with existing quantum secret sharing schemes, it still works when there are dynamic changes, such as the unavailability of some quantum channel, the arrival of new participants and the departure of participants. Finally, we provide security analysis of the new hybrid quantum secret sharing scheme and discuss its useful features for modern applications.

Hybrid threshold adaptable quantum secret sharing scheme with reverse Huffman-Fibonacci-tree coding

Photocatalytic activity and doping effects of BiFeO3 nanoparticles in model organic dyes.

Multiferroic Bi 1- x1 La x FeO 3 ( x = 0.0, 0.1, 0.2, and 0.3) micro-particles were successfully synthesized by a hydrothermal technique. All the samples were phase pure crystallizing in a perovskite structure with a space group of R 3 c . XRD refinement revealed that the lattice parameters increased along with increase of La content, while the Fe–O octahedra became more distorted. It was found that the morphologies of as-obtained micron-sized particles turned from spheroidal to octahedral according to different doping levels. The dielectric constant of Bi 1- x1 La x FeO 3 sample increased after La doping, and reached the largest value for the sample of x = 0.2, both in low and high frequency range at room temperature. All the as-prepared samples exhibited magnetic moments starting above room temperature. It was found that the magnetic moment was significantly enhanced from 0.264 emu/g of BiFeO 3 to 0.658 emu/g of Bi 0.9 La 0.1 FeO 3 in a field of 3 T at 77 K. Both enhancements of ferromagnetic and dielectric properties possibly attribute to the changes of lattice parameters and Fe–O bond lengths caused by lanthanum substitution.

Enhancement of ferromagnetic and dielectric properties in lanthanum doped BiFeO3 by hydrothermal synthesis

Photocatalysis is attracting huge interest for addressing current energy and environmental issues by converting solar light into chemical energy. For this purpose, we investigated the effect of La³⁺ and Se⁴⁺ co-doping on the photocatalytic activity of BiFeO₃. BiFeO₃ and Bi₀.₉₂La₀.₀₈FeO₃ nanoparticles containing different Se⁴⁺ doping content (BiFe₍₁₋ₓ₎SeₓO₃, x = 0.0, 0.02, 0.05, and Bi₀.₉₂La₀.₀₈Fe₍₁₋ₓ₎SeₓO₃, x = 0.0, 0.02, 0.05, 0.075, 0.1) were synthesized by a double solvent sol–gel route. The co-doped nanoparticles were characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and UV-vis diffuse reflectance spectroscopy (DRS), and their photocatalytic activity was studied by the photocatalytic degradation of Congo Red (CR) in aqueous solution under different wavelengths of light illumination. The band-gap of the pure BiFeO₃ was significantly decreased from 2.06 eV to 1.94 eV. It was found that La³⁺ and Se⁴⁺ co-doping significantly affected the photocatalytic performance of pure BiFeO₃. Moreover, with the increment of Se⁴⁺ doping into Bi₀.₉₂La₀.₀₈FeO₃ up to an optimal value, the photocatalytic activity was maximized. In order to study the photosensitization process, photo-degradation of a colourless organic compound (acetophenone) was also observed. On the basis of these experimental results, the enhanced photocatalytic activities with La³⁺ and Se⁴⁺ co-doping could be attributed to the increased optical absorption, and efficient separation and migration of photo-generated charge carriers with the decreased recombination of electrons–holes resulting from co-doping effects. The possible photocatalytic mechanism of La³⁺ and Se⁴⁺ co-doped BiFeO₃ was critically discussed.

Enhanced photocatalytic activity of La³⁺ and Se⁴⁺ co-doped bismuth ferrite nanostructures

Spintronics is a promising technology which aims to solve the major problems existing in today’s conventional electronic devices. Realistically, this technology has the ability to combine the main functions of the modern semiconductor microelectronics and magnetic storage devices in single chip. Electrons have two fundamental degrees of freedom (DOF) called charge and spin. Conventional electronic devices used only the charge of electron for information processing using binary bits 0 and 1. The continuous developments in the conventional electronics are basically depending on reducing component size (transistors, capacitors, etc.) embedded in integrated circuits (random access memory, microprocessor, etc.). In 2019, the actual size of the transistor placed in commercial microprocessor is about 50 nm with gate length of 20 nm and node of 7 nm fabricated using TSMC’s 7-nm FinFET (Taiwan Semiconductor Manufacturing Company 7-nm Fin Field Effect Transistor). The progress in the electronic devices will come to the end when the transistor node size reaches to 1 nm. Below this size, the fabrication, writing, and reading processes will be difficult or impossible due to quantum size effect. Spintronics is the alternative future technology, which is based on using the fundamental spin of electron in additions to its charge to carry and store information. Transfer from conventional electronics to spintronics technology opens the possibilities to construct devices with high storage density, low power consummation, and fast operation and that are cheap and robust. The main aim of this work is to give a simple and clear picture to researchers who are beginners of research in this field. In this review, basic outlines of spintronics technology and its fundamental properties were discussed. Here, we highlight two groups of materials strongly candidates to fabricate spintronics devices, denoted diluted magnetic semiconductor and multiferroic materials.

Spintronics: Future Technology for New Data Storage and Communication Devices

Influence of Mn doping on microstructure, optical, dielectric and magnetic properties of BiFeO3 nanoceramics synthesized via sol–gel method

In order to tailor the multiferroic as well as dielectric properties, we have synthesized BiFeO3 (BFO) and Ni-doped BFO nanoparticles of composition BiFe1-xNixO3 (0 ≤ x ≤ 0.07) via the sol-gel method. The influence of Ni-doping at the Fe site of BiFeO3 on the structural, dielectric, and multiferroic properties was investigated via various characterization techniques such as Raman spectroscopy, vibrating sample magnetometer, polarization-electric field (P-E) loop tracer, and LCR meter. The Raman spectra reveal the rhombohedral distorted perovskite structure of the samples in the R3c space group. The frequency dependent dielectric measurements at room temperature show that the dielectric constant for the pristine sample is an order of magnitude lower than the 1% Ni-doped BFO sample. It is also evident that the ac conductivity increases with the increase in frequency as well as Ni content. Further, the universal dielectric response (UDR) phenomenon is responsible for the dielectric behavior of all the samples in the whole frequency range except for the BiFeO3 and BiFe0.97Ni0.03O3 samples. These samples exhibit deviation from UDR phenomenon at higher frequencies. The room temperature hysteresis (M-H) loops exhibit the saturation in magnetization at higher magnetic fields. The result demonstrates a significant influence on the saturation magnetization with the Ni doping in BFO, prompting the ferromagnetic nature of the samples. The saturation magnetization of the 7% Ni-doped sample is approximately six times higher than the pristine one. The saturated P-E hysteresis loops establish the ferroelectric nature of the synthesized samples that are enhanced significantly on Ni doping. Thus, the doping of Ni in BiFeO3 improves the multiferroic properties of the matrix.

Tailoring dielectric properties and multiferroic behavior of nanocrystalline BiFeO3 via Ni doping

https://iopscience.iop.org/article/10.1088/2053-1591/aac70d/pdf

Significant enhancement in photocatalytic performance of Ni doped BiFeO3 nanoparticles

Correlation between structure, dielectric and multiferroic properties of lead free Ni modified BaTiO3 solid solution

In the present work, we have successfully synthesized graphene oxide (GO) and reduced graphene oxide/magnetite (Gr@Fe 3 O 4 ) nanocomposite (NC) via modified Hummers method and co-precipitation process respectively. Microstructural and physico-chemical properties were investigated through various analytical techniques. XRD and FTIR data analyses revealed highly pure nature of the samples without any other impurity phases. Electron microscopy (SEM/TEM) images of the nanocomposite clearly exhibit uniform and well disperse spherical nanoparticles (NPs) of Fe 3 O 4 over the surface of the graphene sheets. UV-visible absorption spectroscopy indicates a red shift of the absorption band of Gr@Fe 3 O 4 NC as compared to Fe 3 O 4 NPs that suggests π - π noncovalent electrostatic interaction between the magnetic NPs and the graphene surface. The magnetic dispersibility of the NC was also explored using an external magnetic field produced by the simple bar magnets. The results affirm a higher magnetic dispersibility nature of the Gr@Fe 3 O 4 NC than the graphene oxide and Fe 3 O 4 NPs. These behaviour of the NC can be ascribed to synergistic structural and functional effect of Fe 3 O 4 nanoparticles conjugate with graphene sheet.

M. Nadeem

Papers

Influence of Mn doping on microstructure, optical, dielectric and magnetic properties of BiFeO3 nanoceramics synthesized via sol–gel method

Tailoring dielectric properties and multiferroic behavior of nanocrystalline BiFeO3 via Ni doping

Significant enhancement in photocatalytic performance of Ni doped BiFeO3 nanoparticles

Correlation between structure, dielectric and multiferroic properties of lead free Ni modified BaTiO3 solid solution

Synthesis and magnetic dispersibility of magnetite decorated reduced graphene oxide