Structural, Electronic and Magnetic Properties of CaSe Doped with 3d (V, Cr and Mn)

We report first-principles investigation on structural, electronic and magnetic properties of 3d transition metal element-doped rock-salt calcium selenide Ca[Formula: see text]TMxSe (TM = V, Cr and Mn) at concentrations [Formula: see text] = 0.0625, 0.125 and 0.25. We performed the calculations in the framework of the density functional theory (DFT) using the full-potential linearized augmented plane waves plus local orbitals (FP-LAPW+lo) method within the Wu–Cohen generalized gradient approximation (WC-GGA) for the structural optimization and the Tran–Blaha modified Becke–Johnson (TBmBJ) potential for the electronic and the magnetic properties. The computed spin-polarized band structures and densities of states show that Ca[Formula: see text]CrxSe compounds at all studied concentrations are half-metallic ferromagnets with a complete spin polarization of 100% at Fermi-level while the Ca[Formula: see text]VxSe and Ca[Formula: see text]MnxSe are ferromagnetic semiconductors. The total magnetic moments for Ca[Formula: see text]VxSe, Ca[Formula: see text]CrxSe, and Ca[Formula: see text]MnxSe show the integer values of 3[Formula: see text][Formula: see text], 4[Formula: see text][Formula: see text], and 5[Formula: see text][Formula: see text], respectively, with a major contribution of transition metal elements (TM) in the total magnetization. Also, we reported the calculated exchange constants [Formula: see text] and [Formula: see text] and the band edge spin splitting of the valence ([Formula: see text]) and conduction ([Formula: see text]) bands. The ferromagnetism of these compounds is due to the super-exchange and the double-exchange mechanisms in addition to the strong p–d exchange interaction. Therefore, the predicted results indicate that the diluted Ca[Formula: see text]TMxSe (TM = V, Cr, Mn) compounds are suitable candidates for a possible application in the field of spintronic technology.

Dynamic Dipolar Field of Spin Waves in Low-Dimensional Magnetic Systems: The Effects of Translational Symmetry Breaking

Magnon scatterings affect the performance of magnonic devices directly, and dynamic dipolar field (DDF) is crucial in the scattering potential. In this paper, a theoretical model of the DDF in low-dimensional magnetic systems is present, and simulations give the summation area to achieve good accuracy in the DDF calculation, though the dipolar field is a long-range interaction. Calculation in a finite-size thin film indicates that due to the breaking of translational symmetry, the DDF increases evidently in the borders and the corners. The DDF near the vertex of the thin film is several orders magnitude higher than that in the inside area, making the corners prominent in the magnon scatterings.

A Magnetic Reconfigurable Ternary NOR/NAND Logic for Logic-in-Memory Applications

Logic-in memory has emerged as a promising solution to reduce the significant time gap between processor and memory. Simple logics such as NOR and NAND can be embedded in the memory for the purpose of data processing. Besides, ternary logic has been suggested to reduce the interconnects and the complexity of operations. In this paper, a reconfigurable ternary NOR/NAND logic compatible with ternary memories has been proposed. This scheme exploits magnetic tunnel junction as a nonvolatile memory element and a variable resistance, and carbon nanotube field-effect transistor for designing the peripheral circuits to achieve performance and efficiency. The proposed circuit is simulated using HSPICE and the results have validated the correct operation and high performance of the proposed design. Furthermore, the proposed designs are exploited in image processing applications to evaluate their performance in real applications, which gain averagely 52% improvement in the case of data loss.

Structural, Electronic, Magnetic and Mechanical Properties and Magnetocaloric Effect of the Full-Heusler Co2MnGa

Structural, electronic, magnetic and mechanical properties of the Co2MnGa have been calculated with functional density theory using full potential linear augmented plane wave method as implemented in the Wien2k code. Exchange correlation effects for these properties are treated by generalized gradient approximation while for electronic and magnetic properties, in addition to (WC-GGA) correction, mBJ-GGA scheme was also applied. The stiffness constant of the spin wave and the Curie temperature are calculated. Moreover, mechanical parameters included three elastic constants, compression modulus, Young’s modulus and shear modulus are also investigated. This theoretical study provides detailed information on the compound Co2MnGa, in different aspects and can also provide information on the application of this material. Obtained data from ab initio calculations are used as input for Monte Carlo simulations to study the magnetic properties and magnetocaloric effect. Transition temperature, magnetic entropy change, adiabatic temperature change and relative cooling power were found.

Quantum-Inspired Recommendation System with Threshold Proportion Interception

Modern recommendation systems leverage historical behavior information to generate precise recommendation results for users. However, when the data scale of users and items is large, it is difficult to generate recommendation results in time. Tang proposed a quantum-inspired recommendation algorithm, which could solve the recommendation problem in constant time complexity. However, Tang’s approach is based on a set of assumptions which rely heavily on some empirical parameters. The time complexity for calculating parameters is high. Thus, this approach cannot be directly applied in industrial applications. In this paper, we propose a method, namely, Quantum-inspired Recommendation system with threshold Proportion Interception (QRPI), which is based on the quantum-inspired recommendation system and more suitable for industrial environments. Compared with the existing widely used recommendation algorithms, we show through numerical experiments that our solution can achieve almost the same performance with better efficiency.