Observation of flat and weakly dispersing bands in a van der Waals semiconductor Nb3Br8 with breathing kagome lattice

Niobium halides, Nb3X8 (X = Cl,Br,I), which are predicted two-dimensional magnets, have recently gotten attention due to their breathing kagome geometry. Here, we have studied the electronic structure of Nb3Br8 by using angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations. ARPES results depict the presence of multiple flat and weakly dispersing bands. These bands are well explained by the theoretical calculations, which show they have Nb d character indicating their origination from the Nb atoms forming the breathing kagome plane. This van der Waals material can be easily thinned down via mechanical exfoliation to the ultrathin limit and such ultrathin samples are stable as depicted from the time-dependent Raman spectroscopy measurements at room temperature. These results demonstrate that Nb3Br8 is an excellent material not only for studying breathing kagome induced flat band physics and its connection with magnetism, but also for heterostructure fabrication for application purposes.Comment: 24 pages, 12 figures, Supplemental Material include

Observation of momentum-dependent charge density wave gap in a layered antiferromagnet GdTe3{\textrm{Gd}}{\textrm{Te}}_{3} Gd Te 3

Abstract Charge density wave (CDW) ordering has been an important topic of study for a long time owing to its connection with other exotic phases such as superconductivity and magnetism. The $$R{\textrm{Te}}_{3}$$ R Te 3 (R = rare-earth elements) family of materials provides a fertile ground to study the dynamics of CDW in van der Waals layered materials, and the presence of magnetism in these materials allows to explore the interplay among CDW and long range magnetic ordering. Here, we have carried out a high-resolution angle-resolved photoemission spectroscopy (ARPES) study of a CDW material $${\textrm{Gd}}{\textrm{Te}}_{3}$$ Gd Te 3 , which is antiferromagnetic below $$\sim \mathrm {12~K}$$ ∼ 12 K , along with thermodynamic, electrical transport, magnetic, and Raman measurements. Our ARPES data show a two-fold symmetric Fermi surface with both gapped and ungapped regions indicative of the partial nesting. The gap is momentum dependent, maximum along $${\overline{\Gamma }}-\mathrm{\overline{Z}}$$ Γ ¯ - Z ¯ and gradually decreases going towards $${\overline{\Gamma }}-\mathrm{\overline{X}}$$ Γ ¯ - X ¯ . Our study provides a platform to study the dynamics of CDW and its interaction with other physical orders in two- and three-dimensions

Genetic testing and common disorders in a public health framework: how to assess relevance and possibilities

This paper discusses genetic testing and common disorders from a health-care perspective. New possibilities for genetic testing confront health-care workers with the question of whom to test and which test to use. This document focuses on genetic testing and screening in common disorders. The term ¿common disorder¿ is used for disorders that individually have a high impact on public health.Examples of common disorders include cardiovascular disease (CVD), stroke, diabetes, cancer, dementia, and depression. For a health-care practitioner ¿ unlike a geneticist or an epidemiologist ¿ it may not be clear whether a common disorder is due to one gene with a high risk of serious disease, or due to a combination of several genes and several environmental factors. This document will not consider germline prenatal or preconceptional testing, nor testing of biomarkers for tumor recurrence, but it will discuss testing of mutations in tumor tissue, since this may reveal susceptibility to certain forms of therapy. Also, pharmacogenomic applications will not be discussed in depth, although some examples will be given of pharmacogenomic testing. The outlne is as following: First, the terrain of common complex disorders is introduced. Different assessment frames for genetic testing and screening are discussed. The section following that examines the aims and strategies for genetic testing and screening in common disorders and discusses some examples of current testing and screening in Europe. The section ¿The economic evaluation of genetic tests¿ discusses the cost¿benefit relation of different types of tests and screening strategies and how they could be used in the clinic in a cost-effective way. The subsequent section addresses the ethical, legal, and social issues of testing and screening in common disorders. The last section addresses regulatory and intellectual property issues in the EU as well as the United States.JRC.DDG.J.2-The economics of climate change, energy and transpor