Variation of the character of spin-orbit interaction by Pt intercalation underneath graphene on Ir(111)

The modification of the graphene spin structure is of interest for novel possibilities of application of graphene in spintronics. The most exciting of them demand not only high value of spin-orbit splitting of the graphene states, but non-Rashba behavior of the splitting and spatial modulation of the spin-orbit interaction. In this work we study the spin and electronic structure of graphene on Ir(111) with intercalated Pt monolayer. Pt interlayer does not change the 9.3×9.3 superlattice of graphene, while the spin structure of the Dirac cone becomes modified. It is shown that the Rashba splitting of the π state is reduced, while hybridization of the graphene and substrate states leads to a spin-dependent avoided-crossing effect near the Fermi level. Such a variation of spin-orbit interaction combined with the superlattice effects can induce a topological phase in graphene

The Place of Women in the Armed Forces: Legislation and State Compliance with Gender Equality Policies

The purpose of this comparative study is to analyse the challenges and problems faced by women during military service based on the state of gender equality in different countries. The study analysed international law and international judicial practise, which are the driving forces behind making adjustments and changes to the legislation of different countries. The main research method was to compare the existing doctrinal approaches to the study of gender inequality in the armed forces of different countries, to display quantitative indicators of women’s military service in those countries, as well as to analyse and compare the nature of the challenges faced by women during their military service. The study also conducted a thorough analysis of the works of scholars in this area, which confirmed the existence of this problem of gender inequality in the armed forces. It was concluded that the authorised bodies of states should allocate significant resources and efforts to implement measures to ensure the rights of women in the armed forces

Spin structure and spin Hall magnetoresistance of epitaxial thin films of the insulating non-collinear antiferromagnet SmFeO3

We report a combined study of imaging the antiferromagnetic (AFM) spin structure and measuring the spin Hall magnetoresistance (SMR) in epitaxial thin films of the insulating non-collinear antiferromagnet SmFeO3. X-ray magnetic linear dichroism photoemission electron microscopy measurements reveal that the AFM spins of the SmFeO3(1 1 0) align in the plane of the film. Angularly dependent magnetoresistance measurements show that SmFeO3/Ta bilayers exhibit a positive SMR, in contrast to the negative SMR expected in previously studied collinear AFMs. The SMR amplitude increases linearly with increasing external magnetic field at higher magnetic fields, suggesting that field-induced canting of the AFM spins plays an important role. In contrast, around the coercive field, no detectable SMR signal is observed, indicating that the SMR of the AFM and canting magnetization components cancel out. Below 50 K, the SMR amplitude increases sizably by a factor of two as compared to room temperature, which likely correlates with the long-range ordering of the Sm ions. Our results show that the SMR is a sensitive technique for non-equilibrium spin systems of non-collinear AFMs

Identification of Ne l Vector Orientation in Antiferromagnetic Domains Switched by Currents in Ni O Pt Thin Films

Understanding the electrical manipulation of the antiferromagnetic order is a crucial aspect to enable the design of antiferromagnetic devices working at THz frequencies. Focusing on collinear insulating antiferromagnetic NiO Pt thin films as a materials platform, we identify the crystallographic orientation of the domains that can be switched by currents and quantify the N el vector direction changes. We demonstrate electrical switching between different T domains by current pulses, finding that the N el vector orientation in these domains is along [ 5 5 19], different compared to the bulk amp; 10216;112 amp; 10217; directions. The final state of the in plane component of the N el vector nIP after switching by current pulses j along the [1 10] directions is nIP amp; 8741;j. By comparing the observed N el vector orientation and the strain in the thin films, assuming that this variation arises solely from magnetoelastic effects, we quantify the order of magnitude of the magnetoelastic coupling coefficient as b0 2b1 3 107J m3. This information is key for the understanding of current induced switching in antiferromagnets and for the design and use of such devices as active elements in spintronic device

Specific features of the electronic, spin, and atomic structures of a topological insulator Bi2Te2.4Se0.6

The specific features of the electronic and spin structures of a triple topological insulator Bi2Te2.4Se0.6, which is characterized by high-efficiency thermoelectric properties, have been studied with the use of angular- and spin-resolved photoelectron spectroscopy and compared with theoretical calculations in the framework of the density functional theory. It has been shown that the Fermi level for Bi2Te2.4Se0.6 falls outside the band gap and traverses the topological surface state (the Dirac cone). Theoretical calculations of the electronic structure of the surface have demonstrated that the character of distribution of Se atoms on the Te–Se sublattice practically does not influence the dispersion of the surface topological electronic state. The spin structure of this state is characterized by helical spin polarization. Analysis of the Bi2Te2.4Se0.6 surface by scanning tunnel microscopy has revealed atomic smoothness of the surface of a sample cleaved in an ultrahigh vacuum, with a lattice constant of ~4.23 Å. Stability of the Dirac cone of the Bi2Te2.4Se0.6 compound to deposition of a Pt monolayer on the surface is shown.This study was supported by the Ministry of Education and Science of the Russian Federation, the St. Petersburg State University (project nos. 11.38.271.2014 and 15.61.202.2015), and the Russian Foundation for Basic Research (project nos. 12-02-00226, 13-02-91327, 14-08-31110, and 13-02-12110). The research was also performed at the Resource Center “Physical Methods of Surface Investigation” at St. Petersburg State University. We are also grateful to collaborators of the Helmholtz-Zentrum (Berlin) for financial and technical support.Peer reviewe