ABSTRACT
Mott metal-insulator transitions possess electronic, magnetic, and structural degrees of freedom promising next-generation energy-efficient electronics. A previously unknown, hierarchically ordered, and anisotropic supercrystal state is reported and its intrinsic formation characterized in-situ during a Mott transition in a Ca2RuO4 thin film. Machine learning-assisted X-ray nanodiffraction together with cryogenic electron microscopy reveal multi-scale periodic domain formation at and below the film transition temperature (TFilm ≈ 200-250 K) and a separate anisotropic spatial structure at and above TFilm. Local resistivity measurements imply an intrinsic coupling of the supercrystal orientation to the material's anisotropic conductivity. These findings add a new degree of complexity to the physical understanding of Mott transitions, opening opportunities for designing materials with tunable electronic properties.
ABSTRACT
Background: Bipolar disorder is identified as a cause of severe damage to the physical, psychological and social functioning of adolescents and young adults. Aims: The aim of this study is to ascertain the trends in the burden of bipolar disorder among individuals aged 10-24 years at global, regional and national levels from 1990 to 2019. Methods: The data analysed in this study were from the Global Burden of Diseases 2019. The numbers, rates per 100â 000 population, average annual percentage changes (AAPCs) of incidence, prevalence and years lived with disability (YLDs) of bipolar disorder are reported at the global, regional and national levels among individuals aged 10-24 years. Global trends by age, sex and Social Development Index (SDI) were further analysed. Results: Globally, the incidence of bipolar disorder among adolescents and young adults increased from 79.21 per 100 000 population (95% uncertainty interval (UI): 58.13 to 105.15) in 1990 to 84.97 per 100 000 population (95% UI: 61.73 to 113.46) in 2019, AAPC 0.24 (95% confidence interval (CI): 0.22 to 0.26). In the past three decades, there has been an increase in incidence, prevalence and YLDs in both males and females. The largest increase in incidence between 1990 and 2019 was observed in those aged 20-24 years old (from 51.76 per 100 000 population (95% UI: 26.81 to 87.20) in 1990 to 58.37 per 100 000 population (95% UI: 30.39 to 98.55) in 2019; AAPC 0.42 (95% CI: 0.38 to 0.47)). By the SDI quintile, the largest increase in incidence was observed in the middle SDI; however, the high SDI countries had the highest incidence. Regionally, the largest increase in incidence was observed in southern Latin America. At the national level, the most pronounced increase in the incidence was in Greenland. Conclusions: The global increase in incidence among adolescents and young adults between 1990 and 2019 indicates that strategies to improve their mental health still need to be emphasised.
ABSTRACT
New properties and exotic quantum phenomena can form due to periodic nanotextures, including Moire patterns, ferroic domains, and topologically protected magnetization and polarization textures. Despite the availability of powerful tools to characterize the atomic crystal structure, the visualization of nanoscale strain-modulated structural motifs remains challenging. Here, we develop nondestructive real-space imaging of periodic lattice distortions in thin epitaxial films and report an emergent periodic nanotexture in a Mott insulator. Specifically, we combine iterative phase retrieval with unsupervised machine learning to invert the diffuse scattering pattern from conventional X-ray reciprocal-space maps into real-space images of crystalline displacements. Our imaging in PbTiO3/SrTiO3 superlattices exhibiting checkerboard strain modulation substantiates published phase-field model calculations. Furthermore, the imaging of biaxially strained Mott insulator Ca2RuO4 reveals a strain-induced nanotexture comprised of nanometer-thin metallic-structure wires separated by nanometer-thin Mott-insulating-structure walls, as confirmed by cryogenic scanning transmission electron microscopy (cryo-STEM). The nanotexture in Ca2RuO4 film is induced by the metal-to-insulator transition and has not been reported in bulk crystals. We expect the phasing of diffuse X-ray scattering from thin crystalline films in combination with cryo-STEM to open a powerful avenue for discovering, visualizing, and quantifying the periodic strain-modulated structures in quantum materials.
