On the force caused by a null Einstein-Maxwell field with the plane symmetry

The article shows that a large flat platform with a constant current, which flows over its surface, accelerates time. It is also shown that if an alternating current flows along the surface of a flat platform while creating a null electromagnetic field then a force repelling from the platform acts on the test particle located near it. This force has no gravitational nature and arises as a result of the curvature of space-time by the electromagnetic field of a flat platform with an alternating current.

Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with a vertical composition gradient

Current-induced spin-orbit torques (SOTs) are of interest for fast and energy-efficient manipulation of magnetic order in spintronic devices. To be deterministic, however, switching of perpendicularly magnetized materials by SOT requires a mechanism for in-plane symmetry breaking. Existing methods to do so involve the application of an in-plane bias magnetic field, or incorporation of in-plane structural asymmetry in the device, both of which can be difficult to implement in practical applications. Here, we report bias-field-free SOT switching in a single perpendicular CoTb layer with an engineered vertical composition gradient. The vertical structural inversion asymmetry induces strong intrinsic SOTs and a gradient-driven Dzyaloshinskii–Moriya interaction (g-DMI), which breaks the in-plane symmetry during the switching process. Micromagnetic simulations are in agreement with experimental results, and elucidate the role of g-DMI in the deterministic switching processes. This bias-field-free switching scheme for perpendicular ferrimagnets with g-DMI provides a strategy for efficient and compact SOT device design.

Relation Between the Iteration of Planar Retractable Plate Structure and Plane Symmetry Group

One of the most important issues in the design processes of retractable plate structure is to determine the most suitable shape of the plates that form an enclosure without any gaps or overlaps in both closed and open configurations of the structure. One of the approaches to find the most suitable shape of the plates is based on mathematical tessellation technique without using any kinematical or numerical analyses. Due to the usage of RPS on many different areas in architecture, it is just as important to be able to iterate them regularly. This study both focuses on the iteration of planar RPSs that are formed based on 1-uniform tessellation and develops a relation between iteration capacity of RPS and plane symmetry groups. By the help of developed relationship, it tries to realize whether this structure can be derived from 1-uniform tessellation and which tessellation should be selected before obtaining it.

Exploring the electronic band gap of Janus MoSeO and WSeO monolayers and their heterostructures

Designing new two-dimensional (2D) materials based on Janus structure has drawn great attention due to their novel prop erties induced by the out-of-plane symmetry breaking. In this work, we have...

Hybrid model of a stationary plasma thruster

A mathematical model is proposed for studying the processes in a stationary plasma thruster (SPT) taking into account the ionization of the working substance - Xenon, based on the hybrid equations of electromagnetic hydrodynamics (EMHD) of the plasma. The 1D2V case of plane symmetry is considered in detail, for which a numerical algorithm for investigating solutions of hybrid EMHD equations is constructed, based on the method of macroparticles. The solution of a number of fundamental issues is given: the calculation of average values, interpolation, construction of the initial distribution of macroparticles, the choice of boundary conditions for the electric field, etc. The results of calculations with and without taking into account the induction fields in the SPT are presented.