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ZusammenfassungDie pulmonale Hypertonie (PH) ist eine multifaktorielle pulmonalvaskuläre Erkrankung. Bei Patienten mit Belastungsdyspnoe sollte an eine PH als seltene Differenzialdiagnose gedacht werden. Im klinischen Alltag ist die wichtigste Screeningmethode die Echokardiografie. Zentral zur Stellung der Verdachtsdiagnose ist die Bestimmung der maximalen Geschwindigkeit des Regurgitationsjets über der Trikuspidalklappe. Zusätzlich berücksichtigt werden sollten weitere echokardiografische PH-Zeichen wie die Dilatation des rechten Vorhofs oder des Ventrikels. Die Diagnose einer pulmonalen Hypertonie kann abschließend nur im Rechtsherzkatheter gestellt werden. In den neuesten Leitlinien wurde die hämodynamische Definition der PH verändert. Der mittlere pulmonalarterielle Druck zur Diagnosestellung einer PH wurde aktuell auf > 20 mmHg gesenkt. Gerade im Hinblick auf die neue hämodynamische Definition ist die sorgfältige Diagnosestellung in einem erfahrenen PH-Zentrum entscheidend.

International audience; A method is presented to use atomic force microscopy to measure the cleavage energy of van der Waals materials and similar quasi-two-dimensional materials. The cleavage energy of graphite is measured to be 0.36 J/m2, in good agreement with literature data. The same method yields a cleavage energy of 0.6 J/m2 for MoS2 as a representative of the dichalcogenides. In the case of the weak topological insulator Bi14Rh3I9 no cleavage energy is obtained, although cleavage is successful with an adapted approach. The cleavage energies of these materials are evaluated by means of density-functional calculations and literature data. This further validates the presented method and sets an upper limit of about 0.7 J/m2 to the cleavage energy that can be measured by the present setup. In addition, this method can be used as a tool for manipulating exfoliated flakes, prior to or after contacting, which may open a new route for the fabrication of nanostructures.

The unexpected colours of layered sulfides are investigated using spectroscopy and a theoretical defect model approach.

Topological insulators (TIs) gained high interest due to their protected electronic surface states that allow dissipation‐free electron and information transport. In consequence, TIs are recommended as materials for spintronics and quantum computing. Yet, the number of well‐characterized TIs is rather limited. To contribute to this field of research, we focused on new bismuth‐based subiodides and recently succeeded in synthesizing a new compound Bi12Rh3Sn3I9, which is structurally closely related to Bi14Rh3I9 – a stable, layered material. In fact, Bi14Rh3I9 is the first experimentally supported weak 3D TI. Both structures are composed of well‐defined intermetallic layers of ∞ 2[(Bi4Rh)3I]2+ with topologically protected electronic edge‐states. The fundamental difference between Bi14Rh3I9 and Bi12Rh3Sn3I9 lies in the composition and the arrangement of the anionic spacer. While the intermetallic 2D TI layers in Bi14Rh3I9 are isolated by ∞ 1[Bi2I8]2− chains, the isoelectronic substitution of bismuth(III) with tin(II) leads to ∞ 2[Sn3I8]2− layers as anionic spacers. First transport experiments support the 2D character of this material class and revealed metallic conductivity., Insulating: Bi12Rh3Sn3I9, a weak 3D topological insulator (TI) is derived from Bi14Rh3I9, which was the first weakly coupling (“weak”) 3D TI; a bulk semiconductor that hosts protected electronic surface states that allow dissipation‐free electron and information transport due to the specific symmetries of its electronic band structure. In consequence of their topological properties, TIs are envisioned as promising candidates for high‐performance spin field‐effect transistors and quantum bits.

Background: Parametric imaging has taken a steep rise in recent years and non-cardiac applications are of increasing interest. Therefore, the aim of our study was to assess right (RV) and left ventricular (LV) blood pool T1 and T2 values in patients with chronic thromboembolic pulmonary hypertension (CTEPH) compared to control subjects and their correlation to pulmonary hemodynamic. Methods: 26 patients with CTEPH (mean age 64.8 years ± 12.8 SD; 15 female), who underwent CMR and right heart catheterization (RHC) before and 6-months after balloon pulmonary angioplasty (BPA), were retrospectively included. Ventricular blood pool values were measured, compared to control subjects (mean age 40.5 years ± 12.8 SD; 16 female) and correlated to invasive measures (CI, mPAP, PVR). Results: In both, control subjects and CTEPH patients, RVT1 and RVT2 were significantly reduced compared to LVT1 and LVT2. Compared to control subjects, RVT2 was significantly reduced in CTEPH patients (p = 0.0065) and increased significantly after BPA (p = 0.0048). Moreover, RVT2 was positively correlated with CI and negatively correlated with mPAP and PVR before (r = 0.5155, r = −0.2541, r = −0.4571) and after BPA (r = 0.4769, r = −0.2585, r = −0.4396). Conclusion: Ventricular blood pool T2 mapping might be novel non-invasive CMR imaging marker for assessment of disease severity, prognosis, follow-up and even therapy monitoring in PH.

The recent discovery of magnetic topological insulators has opened new avenues to explore exotic states of matter that can emerge from the interplay between topological electronic states and magnetic degrees of freedom, be it ordered or strongly fluctuating. Motivated by the effects that the dynamics of the magnetic moments can have on the topological surface states, we investigate the magnetic fluctuations across the $({\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}){({\mathrm{Bi}}_{2}{\mathrm{Te}}_{3})}_{\mathrm{n}}$ family. Our paramagnetic electron spin resonance experiments reveal contrasting Mn spin dynamics in different compounds, which manifests in a strongly anisotropic Mn spin relaxation in ${\mathrm{MnBi}}_{\text{2}}{\mathrm{Te}}_{\text{4}}$ while being almost isotropic in ${\mathrm{MnBi}}_{\text{4}}{\mathrm{Te}}_{\text{7}}$. Our density-functional calculations explain these striking observations in terms of the sensitivity of the local electronic structure to the Mn spin orientation, and indicate that the anisotropy of the magnetic fluctuations can be controlled by the carrier density, which may directly affect the electronic topological surface states.

Mitochondrial and immune cell dysfunction contributes to the development of pulmonary arterial hypertension (PAH). We thus aimed to investigate mitochondrial respiration and mitochondrial gene expression patterns in the peripheral blood mononuclear cells (PBMC) of patients with idiopathic and hereditary PAH and their correlation to disease parameters. Mitochondrial respiration determined using high-resolution respirometry was not significantly different in PBMC when comparing an outpatient cohort of PAH patients with healthy controls. However, when directly comparing mitochondrial respiration to the hemodynamic parameters of an inpatient PAH cohort, mitochondrial respiration negatively correlated with pulmonary vascular resistance (PVR) and positively correlated with the cardiac index (CI). Furthermore, microarray analysis shows upregulation of mitochondrial erythroid-specific 5-aminolevulinate synthase 2 (ALAS2), as well as the regulation of genes involved in iron and heme metabolism, in the PBMC of patients with PAH, with ALAS2 upregulation in PAH patients being confirmed on the protein level. Multiple regression analysis with age and gender as confounders showed that both PVR and hemoglobin content negatively correlated with maximal respiration. Therefore, we conclude that mitochondrial function in the PBMC of PAH patients is affected by disease severity. However, further studies to investigate cell-type-specific alterations and functional consequences are necessary.

BACKGROUND Pulmonary arterial hypertension restricts the ability of patients to perform routine physical activities. As part of pulmonary arterial hypertension treatment, inhaled iloprost can be administered via a nebulizer that tracks inhalation behavior. Pulmonary arterial hypertension treatment is guided by intermittent clinical measurements, such as 6-minute walk distance, assessed during regular physician visits. Continuous digital monitoring of physical activity may facilitate more complete assessment of the impact of pulmonary arterial hypertension on daily life. Physical activity tracking with a wearable has not yet been assessed with simultaneous tracking of pulmonary arterial hypertension medication intake. OBJECTIVE We aimed to digitally track the physical parameters of patients with pulmonary arterial hypertension who were starting treatment with iloprost using a Breelib nebulizer. The primary objective was to investigate correlations between changes in digital physical activity measures and changes in traditional clinical measures and health-related quality of life over 3 months. Secondary objectives were to evaluate inhalation behavior, adverse events, and changes in heart rate and sleep quality. METHODS We conducted a prospective, multicenter observational study of adults with pulmonary arterial hypertension in World Health Organization functional class III who were adding inhaled iloprost to existing pulmonary arterial hypertension therapy. Daily distance walked, step count, number of standing-up events, heart rate, and 6-minute walk distance were digitally captured using smartwatch (Apple Watch Series 2) and smartphone (iPhone 6S) apps during a 3-month observation period (which began when iloprost treatment began). Before and at the end of the observation period (within 2 weeks), we also evaluated 6-minute walk distance, Borg dyspnea, functional class, B-type natriuretic peptide (or N-terminal pro–B-type natriuretic peptide) levels, health-related quality of life (EQ-5D questionnaire), and sleep quality (Pittsburgh Sleep Quality Index). RESULTS Of 31 patients, 18 were included in the full analysis (observation period: median 91.5 days, IQR 88.0 to 92.0). Changes from baseline in traditional and digital 6-minute walk distance were moderately correlated (r=0.57). Physical activity (daily distance walked: median 0.4 km, IQR –0.2 to 1.9; daily step count: median 591, IQR −509 to 2413) and clinical measures (traditional 6-minute walk distance: median 26 m, IQR 0 to 40) changed concordantly from baseline to the end of the observation period. Health-related quality of life showed little change. Total sleep score and resting heart rate slightly decreased. Distance walked and step count showed short-term increases after each iloprost inhalation. No new safety signals were identified (safety analysis set: n=30). CONCLUSIONS Our results suggest that despite challenges, parallel monitoring of physical activity, heart rate, and iloprost inhalation is feasible in patients with pulmonary arterial hypertension and may complement traditional measures in guiding treatment; however, the sample size of this study limits generalizability. CLINICALTRIAL ClinicalTrials.gov NCT03293407; https://clinicaltrials.gov/ct2/show/NCT03293407 INTERNATIONAL REGISTERED REPORT RR2-10.2196/12144

We have studied potassium-intercalated bulk ${\mathrm{HfS}}_{2}$ and ${\mathrm{HfSe}}_{2}$ by combining transmission electron energy loss spectroscopy, angle-resolved photoemission spectroscopy, and density functional theory calculations. The results reveal insights into (1) the intercalation process itself, (2) its effect on the crystal structures, (3) the induced semiconductor-to-metal transitions, and (4) the accompanying appearance of charge carrier plasmons and their dispersions. Calculations of the formation energies and the evolution of the energies of the charge carrier plasmons as a function of the potassium content show that certain, low potassium concentrations $x$ are thermodynamically unstable. This leads to the coexistence of undoped and doped domains if the provided amount of the alkali metal is insufficient to saturate the whole crystal with the minimum thermodynamically stable potassium stoichiometry. Beyond this threshold concentration the domains disappear, while the alkali metal and charge carrier concentrations increase continuously upon further addition of potassium. At low intercalation levels, electron diffraction patterns indicate a significant degree of disorder in the crystal structure. The initial order in the out-of-plane direction is restored at high $x$ while the crystal layer thicknesses expand by $33--36%$. Calculations suggest that this expansion reaches its maximum at doping levels of $x\ensuremath{\approx}0.25$ before it reverses slightly for higher concentrations. Superstructures emerge parallel to the planes which we attribute to the distribution of the alkali metal rather than structural changes of the host materials. The in-plane lattice parameters change by not more than $1%$. The introduction of potassium causes the formation of charge carrier plasmons whose nature we confirmed by calculating the loss functions and their intraband and interband contributions. The observation of this semiconductor-to-metal transition is supported by calculations of the density of states (DOS) and band structures as well as angle-resolved photoemission spectroscopy. The calculated DOS hint at the presence of an almost ideal two-dimensional electron gas at the Fermi level for $xl0.6$. The plasmons exhibit quadratic momentum dispersions which is in agreement with the behavior expected for an ideal electron gas.

Engineering intramolecular exchange interactions between magnetic metal atoms is a ubiquitous strategy for designing molecular magnets. For lanthanides, the localized nature of 4f electrons usually results in weak exchange coupling. Mediating magnetic interactions between lanthanide ions via radical bridges is a fruitful strategy towards stronger coupling. In this work we explore the limiting case when the role of a radical bridge is played by a single unpaired electron. We synthesize an array of air-stable Ln2@C80(CH2Ph) dimetallofullerenes (Ln2 = Y2, Gd2, Tb2, Dy2, Ho2, Er2, TbY, TbGd) featuring a covalent lanthanide-lanthanide bond. The lanthanide spins are glued together by very strong exchange interactions between 4f moments and a single electron residing on the metal–metal bonding orbital. Tb2@C80(CH2Ph) shows a gigantic coercivity of 8.2 Tesla at 5 K and a high 100-s blocking temperature of magnetization of 25.2 K. The Ln-Ln bonding orbital in Ln2@C80(CH2Ph) is redox active, enabling electrochemical tuning of the magnetism., Dilanthanide complexes that possess radical bridges exhibit enhanced magnetic exchange coupling, affording molecular magnets with high blocking temperatures. Here, the authors explore a series of dilanthanide-encapsulated fullerenes where the radical bridge is taken to its limit and the role is played by a single unpaired electron.

The aim of this study was to assess effects of balloon pulmonary angioplasty (BPA) on right ventricular (RV) mechanical dysfunction in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) via MRI.MRI at 1.5 Tesla and right heart catheterization were performed before and 6 months after BPA in 30 CTEPH patients (mean age 63.4 ± 10.6 years; 17 female). Feature-tracking strain analysis, including global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain, was performed and compared with right ventricular function, myocardial remodelling (assessed by native T1 times), and pulmonary haemodynamics (mean pulmonary arterial pressure and pulmonary vascular resistance).RVEF (35.9% to 48.4%) increased and mPAP (42.1 mmHg to 33.1 mmHg) and PVR (551.8 to 377.7 dyn∙s/cmRV mechanical dysfunction, pulmonary haemodynamics, and myocardial remodelling are markedly improved by BPA. Moreover, RV strain values showed good correlations with RV function, pulmonary haemodynamics, and myocardial remodelling. Therefore, strain analysis might provide new insights regarding therapy outcome, monitoring, and prognosis.

Ba(Fe$_{1/2}$Nb$_{1/2}$)O$_3$ (BFN) ceramics are considered to be promising for technological applications owing to their high dielectric constant over a wide range of temperatures. However, there exists considerable discrepancy over the structural details. We address this discrepancy through a combined x-ray diffraction at room temperature and neutron powder diffraction measurements in the range from 5K up to room temperature, supplemented by a comparative analysis of the earlier reported structures. Our study reveals a cubic structure with space group Pm$\bar{3}$m at all measured temperatures. Further, the x-ray near edge structure and the extended x-ray absorption fine structure studies on the local environment of the Fe ions is consistent with the cubic symmetry. An appropriate value of $U$ for DFT+$U$ calculations is obtained by comparison with x-ray absorption spectroscopy, which agrees well with the earlier reported electronic properties., Comment: 15 pages, 9 figures

The compound Bi14Rh3I9 has recently been suggested as a weak three-dimensional topological insulator on the basis of angle-resolved photoemission and scanning-tunneling experiments in combination with density functional (DF) electronic structure calculations. These methods unanimously support the topological character of the headline compound, but a compelling confirmation could only be obtained by dedicated transport experiments. The latter, however, are biased by an intrinsic n-doping of the materials surface due to its polarity. Electronic reconstruction of the polar surface shifts the topological gap below the Fermi energy, which would also prevent any future device application. Here, we report the results of DF slab calculations for chemically gated and counter-doped surfaces of Bi14Rh3I9. We demonstrate that both methods can be used to compensate the surface polarity without closing the electronic gap., Comment: 17 pages, 7 figures, Accepted

With increasing temperature, Sr 2 ScSbO 6 undergoes three structural phase transitions at approximately 400 K , 560 K and 650 K , leading to the following sequence of phases: P 2 1 / n → I 2 / m → I 4 / m → F m 3 ¯ m , making it an ideal candidate to study the effects of octahedral tilting while keeping other parameters fixed. To ascertain the isolated effects of octahedral distortions, the electronic and optical properties of the monoclinic P 2 1 / n (at room temperature), monoclinic I 2 / m (at 430 K ), tetragonal I 4 / m (at 613 K ) and the cubic F m 3 ¯ m (at 660 K ) phases have been studied in terms of the electronic structure, dielectric constant, optical conductivity and electron energy loss spectrum using density functional theory. Ca 2 ScSbO 6 , on the other hand, shows only a P 2 1 / n phase at room temperature and its properties have been compared with the corresponding Sr compound. UV–Vis spectroscopic studies of the optical properties of the room-temperature phase of these d 0 double perovskites have been performed and presence of large direct bandgap for both the compounds have been reported. The electronic bandgaps for the room temperature phases are found to be in good agreement with the corresponding experimental values obtained using the Kubelka-Munk function. Interestingly, in contrast to other Sc-based d 0 double perovskites, with increasing octahedral distortions, the effective t 2 g bandwidth remains unaffected while the states forming the band change due to changes in unit cell orientation, leading to small effects on the electronic and optical properties.

As they do not rely on the presence of any crystal symmetry, Weyl nodes are robust topological features of an electronic structure that can occur at any momentum and energy. Acting as sinks and sources of Berry curvature, Weyl nodes have been predicted to strongly affect the transverse electronic response, like in the anomalous Hall or Nernst effects. However, to observe large anomalous effects the Weyl nodes need to be close to or at the Fermi-level, which implies the band structure must be tuned by an external parameter, e.g. chemical doping or pressure. Here we show that in a ferromagnetic metal tuning of the Weyl node energy and momentum can be achieved by rotation of the magnetization. Taking Co$_3$Sn$_2$S$_2$ as an example, we use electronic structure calculations based on density-functional theory to show that not only new Weyl fermions can be created by canting the magnetization away from the easy axis, but also that the Weyl nodes can be driven exactly to the Fermi surface. We also show that the dynamics in energy and momentum of the Weyl nodes strongly affect the calculated anomalous Hall and Nernst conductivities., Comment: Supp. Material added

RA STRAIN SUPPLEMENT

Iridate oxides on a honeycomb lattice are considered promising candidates for realization of quantum spin liquid states. We investigate the magnetic couplings in a structural model for a honeycomb iridate K$_2$IrO$_3$, with $C_3$ point group symmetry at the Ir sites, which is an end member of the recently synthesized iridate family K$_x$Ir$_y$O$_2$. Using \textit{ab-initio} quantum chemical methods, we elucidate the subtle relationship between the real space symmetry and magnetic anisotropy and show that the higher point group symmetry leads to high frustration with strong magnetic anisotropy driven by the unusually large off-diagonal exchange couplings ($\Gamma$'s) as opposed to other spin-liquid candidates considered so far. Consequently, large quantum fluctuations imply lack of magnetic ordering consistent with the experiments. Exact diagonalization calculations for the fully anisotropic $K$-$J$-$\Gamma$ Hamiltonian reveal the importance of the off-diagonal anisotropic exchange couplings in stabilizing a spin liquid state and highlight an alternative route to stabilize spin liquid states for ferromagnetic $K$., Comment: 8 pages, 3 figures, and Supplemental Material

Compound Bi14Rh3I9 consists of ionic stacks of intermetallic [(Bi4Rh)3I](2+) and insulating [Bi2I8](2-) layers and has been identified to be a weak topological insulator. Scanning tunneling microscopy revealed the robust edge states at all step edges of the cationic layer as a topological fingerprint. However, these edge states are found 0.25 eV below the Fermi level, which is an obstacle for transport experiments. Here, we address this obstacle by comparing results of density functional slab calculations with scanning tunneling spectroscopy and angle-resolved photoemission spectroscopy. We show that the n-type doping of the intermetallic layer is intrinsically caused by the polar surface and is well-screened toward the bulk. In contrast, the anionic "spacer" layer shows a gap at the Fermi level, both on the surface and in the bulk; that is, it is not surface-doped due to iodine desorption. The well-screened surface dipole implies that a buried edge state, probably already below a single spacer layer, is located at the Fermi level. Consequently, a multilayer step covered by a spacer layer could provide access to the transport properties of the topological edge states. In addition, we find a lateral electronic modulation of the topologically nontrivial surface layer, which is traced back to the coupling with the underlying zigzag chain structure of the spacer layer.

Physica status solidi. B Basic research 2000060 (2020). doi:10.1002/pssb.202000060, Published by Wiley-VCH, Weinheim

The kagome lattice based on 3d transition metals is a versatile platform for novel topological phases hosting symmetry-protected electronic excitations and exotic magnetic ground states. However, the paradigmatic states of the idealized two-dimensional (2D) kagome lattice - Dirac fermions and topological flat bands - have not been simultaneously observed, partly owing to the complex stacking structure of the kagome compounds studied to date. Here, we take the approach of examining FeSn, an antiferromagnetic single-layer kagome metal with spatially-decoupled kagome planes. Using polarization- and termination-dependent angle-resolved photoemission spectroscopy (ARPES), we detect the momentum-space signatures of coexisting flat bands and Dirac fermions in the vicinity of the Fermi energy. Intriguingly, when complemented with bulk-sensitive de Haas-van Alphen (dHvA) measurements, our data reveal an even richer electronic structure that exhibits robust surface Dirac fermions on specific crystalline terminations. Through band structure calculations and matrix element simulations, we demonstrate that the bulk Dirac bands arise from in-plane localized Fe-3d orbitals under kagome symmetry, while the surface state realizes a rare example of fully spin-polarized 2D Dirac fermions when combined with spin-layer locking in FeSn. These results highlight FeSn as a prototypical host for the emergent excitations of the kagome lattice. The prospect to harness these excitations for novel topological phases and spintronic devices is a frontier of great promise at the confluence of topology, magnetism, and strongly-correlated electron physics.

The International Conference on Magnetism 2009 (ICM 2009) was held in Karlsruhe, Germany, from 26 to 31 July 2009. Previous conferences in this series were organized in Edinburgh, UK (1991), Warsaw, Poland (1994), Cairns, Australia (1997), Recife, Brazil (2000), Rome, Italy (2003), and Kyoto, Japan (2006). As with previous ICM conferences, the annual Conference on Strongly Correlated Electron Systems (SCES) was integrated into ICM 2009. The topics presented at ICM 2009 were strongly correlated electron systems, quantum and classical spin systems, magnetic structures and interactions, magnetization dynamics and micromagnetics, spin-dependent transport, spin electronics, magnetic thin films, particles and nanostructures, soft and hard magnetic materials and their applications, novel materials and device applications, magnetic recording and memories, measuring techniques and instrumentation, as well as interdisciplinary topics. We are grateful to the International Advisory Committee for their help in coordinating an attractive program encompassing practically all aspects of magnetism, both experimentally and theoretically. The Program Committee comprised A Loidl, Germany (Chair), M A Continentino, Brazil, D E Dahlberg, USA, D Givord, France, G Guntherodt, Germany, H Mikeska, Germany, D Kaczorowski, Poland, Ching-Ray Chang, South Korea, I Mertig, Germany, D Vollhardt, Germany, and E F Wassermann, Germany. E F Wassermann was also head of the National Organizing Committee. His help is gratefully acknowledged. The scientific program started on Monday 27 July 2009 with opening addresses by the Conference Chairman, the Deputy Mayor of Karlsruhe, Ms M Mergen and the Chairman of the Executive Board of Forschungszentrum Karlsruhe, E Umbach. ICM 2009 was attended by the Nobel Laureates P W Anderson, A Fert and P Grunberg who gave plenary talks. A special highlight was the presentation of the Magnetism Award and Neel Medal to S S P Parkin who also presented his newest results in a plenary talk. The IUPAP Young Scientist Award on Magnetism was presented to S O Valenzuela, E Saitoh and T Kimura. The sessions were held in the Stadthalle Karlsuhe operated by the Karlsruher Messe- und Kongress-GmbH (KMK). We are grateful to Ms M Makelburg (KMK) for organizing the conference site impeccably. The conference was attended by 1552 participants from 48 countries, with approximately 50 per cent from overseas. The program entailed six plenary talks (40 min each), with 16 half-plenary and 41 invited talks (30 min) and 298 contributed talks (15 min). Extended lunch breaks and evenings were devoted to poster sessions, with a total of 1632 posters presented. All submitted papers were reviewed in order to meet the standards of Journal of Physics: Condensed Matter and Journal of Physics: Conference Series. The referees made every effort to ensure that the manuscripts submitted for publication in the proceedings reached a high standard. The tremendous work in organizing the paper classification and refereeing procedures was carried out by the Publication Committee which was headed by J Wosnitza, and comprised, in addition, Th Pruschke, M Richter and L Schultz. We also thank G Douglas, IOP Publishing, for his support with the preparation of these proceedings. We gratefully acknowledge the help of L Behrens, E Maass and B Schelske in preparing the conference. The conference would not have been possible without G Goll (conference secretary) and C Surgers (finances). I thank them for their help. Thanks also go to the many students in blue t-shirts who helped to manage the conference. We are grateful for the financial support of Universitat Karlsruhe (TH) and Forschungszentrum Karlsruhe (both institutions merged to form the Karlsruhe Institute of Technology (KIT) as of 1 October 2009), the International Union of Pure and Applied Physics (IUPAP), the City of Karlsruhe, Deutsche Forschungsgemeinschaft (German National Science Foundation), and the European Commission through COST MPNS Action P16. Hilbert v Lohneysen Conference Chairman of ICM 2009 Karlsruhe Institute of Technology, Germany

We investigate the lattice dynamical properties of Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au in the nonequilibrium hcp structure by means of density-functional simulations, wherein spin-orbit coupling (SO ...

Topologically protected states with a natural helicity are shown to form at step edges, which can be created with subnanometre precision in a weak topological insulator using atomic force microscopy.

The long search for materials carrying quantum spin liquid states has recently led to $\ensuremath{\alpha}$-RuCl${}_{3}$, a layered honeycomb Mott insulator with substantial spin-orbit coupling. Often, controlled doping of materials with strong 2D character generates new exotic properties as well as a better understanding of the parent compound. This paper shows that the intercalation compound K${}_{0.5}$RuCl${}_{3}$ sustains a peculiar charge disproportionation into formally Ru${}^{2+}$ and Ru${}^{3+}$. Every Ru${}^{3+}$ with one hole in the t${}_{2g}$ shell is surrounded by Ru${}^{2+}$ where the t${}_{2g}$ level is full and magnetically inert. Thus each type of Ru sites forms a triangular lattice and nearest-neighbor interactions of the original honeycomb are blocked.

The compound Bi

The ferromagnetic semiconductor $\mathrm{B}{\mathrm{a}}_{2}\mathrm{NiOs}{\mathrm{O}}_{6}$ (${T}_{\mathrm{mag}}\ensuremath{\sim}100\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) was synthesized at 6 GPa and 1500 \ifmmode^\circ\else\textdegree\fi{}C. It crystallizes into a double perovskite structure [$Fm\ensuremath{-}3m$; $a=8.0428(1)\phantom{\rule{0.16em}{0ex}}\AA{}$], where the $\mathrm{N}{\mathrm{i}}^{2+}$ and $\mathrm{O}{\mathrm{s}}^{6+}$ ions are perfectly ordered at the perovskite $B$ site. We show that the spin-orbit coupling of $\mathrm{O}{\mathrm{s}}^{6+}$ plays an essential role in opening the charge gap. The magnetic state was investigated by density functional theory calculations and powder neutron diffraction. The latter revealed a collinear ferromagnetic order in a $g21\phantom{\rule{0.16em}{0ex}}\mathrm{kOe}$ magnetic field at 5 K. The ferromagnetic gapped state is fundamentally different from that of known dilute magnetic semiconductors such as (Ga,Mn)As and (Cd,Mn)Te (${T}_{\mathrm{mag}}l180\phantom{\rule{0.16em}{0ex}}\mathrm{K}$), the spin-gapless semiconductor $\mathrm{M}{\mathrm{n}}_{2}\mathrm{CoAl}$ (${T}_{\mathrm{mag}}\ensuremath{\sim}720\phantom{\rule{0.16em}{0ex}}\mathrm{K}$), and the ferromagnetic insulators EuO (${T}_{\mathrm{mag}}\ensuremath{\sim}70\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) and $\mathrm{B}{\mathrm{i}}_{3}\mathrm{C}{\mathrm{r}}_{3}{\mathrm{O}}_{11}$ (${T}_{\mathrm{mag}}\ensuremath{\sim}220\phantom{\rule{0.16em}{0ex}}\mathrm{K}$). It is also qualitatively different from known ferrimagnetic insulators and semiconductors, which are characterized by an antiparallel spin arrangement. Our finding of the ferromagnetic semiconductivity of $\mathrm{B}{\mathrm{a}}_{2}\mathrm{NiOs}{\mathrm{O}}_{6}$ should increase interest in the platinum group oxides, because this alternative class of materials should be useful in the development of spintronic, quantum magnetic, and related devices.

Because of the outstanding high theoretical specific energy density of 2600 Wh kg(-1), the lithium-sulfur (Li-S) battery is regarded as a promising candidate for post lithium-ion battery systems eligible to meet the forthcoming market requirements. However, its commercialization on large scale is thwarted by fast capacity fading caused by the Achilles' heel of Li-S systems: the polysulfide shuttle. Here, we merge the physical features of carbon-coated separators and the unique chemical properties of N and S codoped mesoporous carbon to create a functional hybrid separator with superior polysulfide affinity and electrochemical benefits. DFT calculations revealed that carbon materials with N and S codoping possess a strong binding energy to high-order polysulfide species, which is essential to keep the active material in the cathode side. As a result of the synergistic effect of N, S dual-doping, an advanced Li-S cell with high specific capacity and ultralow capacity degradation of 0.041% per cycle is achieved. Pushing our simple-designed and scalable cathode to a highly increased sulfur loading of 5.4 mg cm(-2), the Li-S cell with the functional hybrid separator can deliver a remarkable areal capacity of 5.9 mAh cm(-2), which is highly favorable for practical applications.

NTRODUCTION The reproducibility of results is one of the underlying principles of science. An observation can only be accepted by the scientific community when it can be confirmed by independent studies. However, reproducibility does not come easily. Recent works have painfully exposed cases where previous conclusions were not upheld. The scrutiny of the scientific community has also turned to research involving computer programs, finding that reproducibility depends more strongly on implementation than commonly thought. These problems are especially relevant for property predictions of crystals and molecules, which hinge on precise computer implementations of the governing equation of quantum physics. RATIONALE This work focuses on density functional theory (DFT), a particularly popular quantum method for both academic and industrial applications. More than 15,000 DFT papers are published each year, and DFT is now increasingly used in an automated fashion to build large databases or apply multiscale techniques with limited human supervision. Therefore, the reproducibility of DFT results underlies the scientific credibility of a substantial fraction of current work in the natural and engineering sciences. A plethora of DFT computer codes are available, many of them differing considerably in their details of implementation, and each yielding a certain “precision” relative to other codes. How is one to decide for more than a few simple cases which code predicts the correct result, and which does not? We devised a procedure to assess the precision of DFT methods and used this to demonstrate reproducibility among many of the most widely used DFT codes. The essential part of this assessment is a pairwise comparison of a wide range of methods with respect to their predictions of the equations of state of the elemental crystals. This effort required the combined expertise of a large group of code developers and expert users. RESULTS We calculated equation-of-state data for four classes of DFT implementations, totaling 40 methods. Most codes agree very well, with pairwise differences that are comparable to those between different high-precision experiments. Even in the case of pseudization approaches, which largely depend on the atomic potentials used, a similar precision can be obtained as when using the full potential. The remaining deviations are due to subtle effects, such as specific numerical implementations or the treatment of relativistic terms. CONCLUSION Our work demonstrates that the precision of DFT implementations can be determined, even in the absence of one absolute reference code. Although this was not the case 5 to 10 years ago, most of the commonly used codes and methods are now found to predict essentially identical results. The established precision of DFT codes not only ensures the reproducibility of DFT predictions but also puts several past and future developments on a firmer footing. Any newly developed methodology can now be tested against the benchmark to verify whether it reaches the same level of precision. New DFT applications can be shown to have used a sufficiently precise method. Moreover, high-precision DFT calculations are essential for developing improvements to DFT methodology, such as new density functionals, which may further increase the predictive power of the simulations.