Capability of international law to resolve an ethnic conflict: case of Bosnia and Herzegovina

Práce se zabývá komplexní otázkou schopnosti mezinárodního práva řešit národnostní konflikt a vychází přitom z případové studie daytonského systému v Bosně a Hercegovině. Snahou je zaujmout interdisciplinární přístup a zaměřit se nikoli pouze na právní otázky, ale zhodnotit také sociologické a další relevantní aspekty. V prvních kapitolách jsou shrnuty návrhy mírového řešení předcházející Daytonu, na ně navazuje právní analýza přijatých dohod a dále rozsáhlá analýza nejvýznamnějších a nejviditelnějších aspektů jejich implementace. Poslední kapitola se poté zabývá tématem z hlediska řešení konfliktů. V úvodu je formulováno několik klíčových otázek: Je mezinárodní právo schopno vyloučit možnost znovuvypuknutí ozbrojeného konfliktu v Bosně? Jsou jeho limity či chybná aplikace bezprostřední příčinou současného stavu? Stal se v případě Bosny a Hercegoviny mezinárodní režim zcela odtržen od sociologického substrátu? Při hledání odpovědí je značná pozornost věnována vnímání a přijímání daytonského systému jednotlivými zájmovými skupinami v rámci bosenské společnosti, stejně jako dalšímu působení mezinárodního společenství v zemi.' Z provedené analýzy vyplývá, že daytonský systém je přežitý a není schopen nadále tvořit základní kámen bosenského politického systému. Jeví se, že mezinárodní společenství by...Title Capability of international law to resolve an ethnic conflict: case of Bosnia and Herzegovina Abstract The thesis deals with the complex issue of international law's capability to resolve an ethnic conflict, relying to a great extent on a case study of the Dayton system in Bosnia and Herzegovina. It aims to take an interdisciplinary approach, focusing not only on legal issues but also on sociological and other relevant aspects. The first chapters attempt to summarize peace proposals preceding Dayton and are followed by a legal analysis of the adopted documents and a subsequent thorough examination of the most significant and visible aspects of their implementation. The last chapter then reviews the topic from the standpoint of conflict resolution. Several key questions are formulated in the preface: Is international law able to deter the risk of yet another outbreak of armed conflict in Bosnia? Are its limits or flawed imposition the immediate cause of the present state? Has the international regime in Bosnia become completely dissasociated from the sociological substratum? Whilst seeking for answers, much attention is paid to the perception and reception of the Dayton system by various interest groups within Bosnia's society as well as to international community's ensuing engagement in the country....Department of Public International LawKatedra mezinárodního právaFaculty of LawPrávnická fakult

Crystal Hall effect in Collinear Antiferromagnets

Electrons, commonly moving along the applied electric field, acquire in certain magnets a dissipationless transverse velocity. This spontaneous Hall effect, discovered more than a century ago, has been understood in terms of the time-reversal symmetry breaking by the internal spin-structure of a ferromagnetic, noncolinear antiferromagnetic or skyrmionic form. Here we identify previously overlooked robust Hall effect mechanism arising from collinear antiferromagnetism combined with nonmagnetic atoms at non-centrosymmetric positions. We predict a large magnitude of this crystal Hall effect in a room-temperature collinear antiferromagnet RuO$_2$ and catalogue, based on our symmetry rules, extensive families of material candidates. We show that the crystal Hall effect is accompanied by the possibility to control its sign by the crystal chirality. We illustrate that accounting for the full magnetization density distribution instead of the simplified spin-structure sheds new light on symmetry breaking phenomena in complex magnets and opens an alternative avenue towards quantum materials engineering for low-dissipation nanoelectronics.Comment: 21 pages, 5 figure

Exchange spin-orbit coupling and unconventional p-wave magnetism

Spin-orbit coupling arising from the relativistic Dirac equation underpins fundamental and applied research areas such as the spin Hall effects and topological insulators. This Dirac mechanism of spin-orbit coupling induces in non-centrosymmetric crystals a momentum-dependent spin splitting typically limited to a meV scale unless involving heavy and often toxic elements. Here we identify a previously overlooked mechanism that shares with the Dirac mechanism the characteristic signature of spin-orbit coupling, namely the antisymmetric time-reversal-invariant spin polarization in the band structure. In contrast to the relativistic Dirac equation, our spin-orbit coupling arises from the magnetic exchange interaction in non-centrosymmetric crystals with a non-coplanar spin order. An unconventional p-wave magnetic phase, corresponding to this exchange spin-orbit coupling, represents a long-sought but elusive realization of a magnetic counterpart of the p-wave phase of superfluid He-3. We identify type-A exchange spin-orbit coupling realized on mutually-shifted opposite-spin Fermi surfaces, and type-B on one Fermi surface. We predict giant spin splitting magnitudes on the scale of hundreds of meV in realistic material candidates, namely in antiperovskite Ce$_3$InN and Mn$_3$GaN. Our results open a possibility for realizing large exchange spin-orbit coupling phenomena in materials comprising abundant light elements and with implications in fields ranging from spintronics, dissipationless nanoelectronics and quantum electronics, to topological matter.Comment: 10 pages, 4 figure

Giant and tunneling magnetoresistance effects from anisotropic and valley-dependent spin-momentum interactions in antiferromagnets

Giant or tunneling magnetoresistance are physical phenomena used for reading information in commercial spintronic devices. The effects rely on a conserved spin current passing between a reference and a sensing ferromagnetic electrode in a multilayer structure. Recently, we have proposed that these fundamental spintronic effects can be realized in collinear antiferromagnets with staggered spin-momentum exchange interaction, which generates conserved spin currents in the absence of a net equilibrium magnetization. Here we elaborate on the proposal by presenting archetype model mechanisms for the antiferromagnetic giant and tunneling magnetoresistance effects. The models are based, respectively, on anisotropic and valley-dependent forms of the non-relativistic staggered spin-momentum interaction. Using first principles calculations we link these model mechanisms to real antiferromagnetic materials and predict a $\sim$100\% scale for the effects. We point out that besides the GMR/TMR detection, our models directly imply the possibility of spin-transfer-torques excitation of the antiferromagnets.Comment: 6 pages, 4 figure

Different types of spin currents in the comprehensive materials database of nonmagnetic spin Hall effect

Spin Hall effect (SHE) has its special position in spintronics. To gain new insight into SHE and to identify materials with substantial spin Hall conductivity (SHC), we performed high-precision high-throughput ab initio calculations of the intrinsic SHC for over 20,000 nonmagnetic crystals. The calculations revealed a strong relationship between the magnitude of the SHC and the crystalline symmetry, where a large SHC is typically associated with mirror symmetry-protected nodal line band structures. This database includes 11 materials with an SHC comparable to or even larger than that of Pt. Materials with different types of spin currents were additionally identified. Furthermore, we found that different types of spin current can be obtained by rotating applied electrical fields. This improves our understanding and is expected to facilitate the design of new types of spin-orbitronic devices

Terahertz probing of anisotropic conductivity and morphology of CuMnAs epitaxial thin films

Antiferromagnetic CuMnAs thin films have attracted attention since the discovery of the manipulation of their magnetic structure via electrical, optical, and terahertz pulses of electric fields, enabling convenient approaches to the switching between magnetoresistive states of the film for the information storage. However, the magnetic structure and, thus, the efficiency of the manipulation can be affected by the film morphology and growth defects. In this study, we investigate the properties of CuMnAs thin films by probing the defect-related uniaxial anisotropy of electric conductivity by contact-free terahertz transmission spectroscopy. We show that the terahertz measurements conveniently detect the conductivity anisotropy, that are consistent with conventional DC Hall-bar measurements. Moreover, the terahertz technique allows for considerably finer determination of anisotropy axes and it is less sensitive to the local film degradation. Thanks to the averaging over a large detection area, the THz probing also allows for an analysis of strongly non-uniform thin films. Using scanning near-field terahertz and electron microscopies, we relate the observed anisotropic conductivity of CuMnAs to the elongation and orientation of growth defects, which influence the local microscopic conductivity. We also demonstrate control over the morphology of defects by using vicinal substrates.Comment: 33 pages, 16 figure

Efficient Electrical Spin Splitter Based on Nonrelativistic Collinear Antiferromagnetism

Electrical spin-current generation is among the core phenomena driving the field of spintronics. Using {\em ab initio} calculations we show that a room-temperature metallic collinear antiferromagnet RuO$_2$ allows for highly efficient spin-current generation, arising from anisotropically-split bands with conserved up and down spins along the N\'eel vector axis. The zero net moment antiferromagnet acts as an electrical spin-splitter with a 34$^\circ$ propagation angle between spin-up and spin-down currents. Correspondingly, the spin-conductivity is a factor of three larger than the record value from a survey of 20,000 non-magnetic spin-Hall materials. We propose a versatile spin-splitter-torque concept utilizing antiferromagnetic RuO$_2$ films interfaced with a ferromagnet.Comment: 6 pages, 4 figure

Temperature-dependent resistivity and anomalous Hall effect in NiMnSb from first principles

© 2019 American Physical Society. We present implementation of the alloy analogy model within fully relativistic density-functional theory with the coherent potential approximation for a treatment of nonzero temperatures. We calculate contributions of phonons and magnetic and chemical disorder to the temperature-dependent resistivity, anomalous Hall conductivity (AHC), and spin-resolved conductivity in ferromagnetic half-Heusler NiMnSb. Our electrical transport calculations with combined scattering effects agree well with experimental literature for Ni-rich NiMnSb with 1-2% Ni impurities on Mn sublattice. The calculated AHC is dominated by the Fermi surface term in the Kubo-Bastin formula. Moreover, the AHC as a function of longitudinal conductivity consists of two linear parts in the Ni-rich alloy, while it is nonmonotonic for Mn impurities. We obtain the spin polarization of the electrical current P>90% at room temperature and we show that P may be tuned by chemical composition. The presented results demonstrate the applicability of an efficient first-principles scheme to calculate temperature dependence of linear transport coefficients in multisublattice bulk magnetic alloys

Molecular beam epitaxy of CuMnAs

We present a detailed study of the growth of the tetragonal polymorph of antiferromagnetic CuMnAs by the molecular beam epitaxy technique. We explore the parameter space of growth conditions and their effect on the microstructural and transport properties of the material. We identify its typical structural defects and compare the properties of epitaxial CuMnAs layers grown on GaP, GaAs and Si substrates. Finally, we investigate the correlation between the crystalline quality of CuMnAs and its performance in terms of electrically induced resistance switching.Comment: 10 pages, 8 figures and supplementary materia