Elementary Building Blocks for Cluster Mott Insulators

<p>Mott insulators, in which strong Coulomb interactions fully localize electrons on single atomic sites, play host to an incredibly rich and exciting array of strongly correlated physics. One can naturally extend this concept to cluster Mott insulators, wherein electrons localize not on single atoms but across clusters of atoms, forming "molecules in solids''. The resulting localized degrees of freedom incorporate the full spectrum of electronic degrees of freedom, spin, orbital, and charge. These serve as the building blocks for cluster Mott insulators, and understanding them is an important first step toward understanding the many-body physics that emerges in candidate cluster Mott insulators. Here, we focus on elementary building blocks, neglecting some of the complexity present in real materials which can often obfuscate the underlying principles at play. Through an extensive set of exact theoretical calculations on clusters of varying geometry, number of orbitals, and number of electrons, we uncover some of the basic organizing principles of cluster Mott phases, particularly when interactions dominate and negate a simple single-particle picture.</p><p>In the accompanying paper (see link), we presented illustrative phase diagrams for different cluster geometries and select electron fillings. Here, we present the raw data and phase diagrams for all the remaining electron fillings on all cluster geometries obtained from exact diagonalization. The data is presented in Arrow files, with each Arrow file containing data such as eigenvalues, eigenvectors, ground state degeneracies, and various quantum numbers for a 21x21 U-J grid for all electron fillings, with the specific hopping values specified in the file name. The plots in the dataset have been derived from the respective raw data files.</p&gt

Responsive mental health systems to address the poverty, homelessness and mental illness nexus: The Banyan experience from India

Background: Mental health has gained prominence as a global public health priority. However, a substantial treatment gap persists in many low- and middle-income countries. Within this scenario, the nexus between homelessness, poverty and mental illness represents a particularly complex issue. This article presents the experience of The Banyan, a 25 years old non-profit organisation providing mental health care to people living in poverty in Tamil Nadu, India. Case presentation: The case study describes the evolution of The Banyan using a timeline narrative. By applying an action learning framework, the organisation's evolution through four lifecycles, strategy and the key elements underlying mental health system responses are identified and presented. 'User centred' and 'service integration' emerge as the main dimensions of The Banyan's responsive health system. Relating to these two attributes, a typology of services is derived, indicating the responsiveness of mental health systems in addressing complex problems. The role of the organisational culture and the expressed values during the transition is considered. Conclusions: The case study serves as an example of how responsive mental health systems may be constructed with both a user centred and a service integration focus