We formulate a universal characterization of the many-particle quantum entanglement in the ground state of a topologically ordered two-dimensional medium with a mass gap. We consider a disk in the plane, with a smooth boundary of length L, large compared to the correlation length. In the ground state, by tracing out all degrees of freedom in the exterior of the disk, we obtain a marginal density operator rho for the degrees of freedom in the interior. The von Neumann entropy of rho, a measure of the entanglement of the interior and exterior variables, has the form S(rho) = alphaL - gamma + ..., where the ellipsis represents terms that vanish in the limit L --> infinity. We show that - gamma is a universal constant characterizing a global feature of the entanglement in the ground state. Using topological quantum field theory methods, we derive a formula for gamma in terms of properties of the superselection sectors of the medium.
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http://dx.doi.org/10.1103/PhysRevLett.96.110404 | DOI Listing |
Rev Esc Enferm USP
January 2025
Universidade Estadual de Campinas, Faculdade de Enfermagem, Campinas, SP, Brazil.
Objective: To understand the experience of children with special health needs at school.
Method: Qualitative research using Symbolic Interactionism as a theoretical framework and assumptions of Grounded Theory as a methodological framework. Data collected in a pediatric outpatient clinic of a teaching hospital in an inland city of the state of São Paulo.
Angew Chem Int Ed Engl
January 2025
TU Dortmund: Technische Universitat Dortmund, Fakultät für Chemie und Chemische Biologie, Otto-Hahn Str.6, 44227, Dortmund, GERMANY.
This study introduces a novel class of carbon-centered diradicals: a monosubstituted C-atom stabilized by a phosphine. The diradical Ph3P→C was photochemically generated from a diazophosphorus ylide precursor (Ph3PCN2) and characterized by EPR and isotope-sensitive ENDOR spectroscopy at low temperatures. Ph3P→C features an axial zero-field splitting parameter D = 0.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States.
The hydrothermal synthesis of novel materials typically relies on both knowledge of the redox activities of all cations present in the reaction solution and a small toolset of so-called mineralizers to tune the solution's overall chemical potential. Upon the use of a less conventional mineralizer species, SiO, we show the stabilization of spiroffite-type CoTeO under less forceful hydrothermal conditions than those in previous reports. When synthesized in the presence of both SiO and each respective alkali carbonate as a secondary mineralizer, silicon substitution in place of tellurium in the host structure becomes apparent, and the corresponding disorder introduced gives rise to enhanced low-temperature ferromagnetism.
View Article and Find Full Text PDFChemistry
January 2025
Jadavpur University, Chemistry, 188 Raja S. C. Mallick Road, 700032, Kolkata, INDIA.
Two π-radical complexes containing bisazo-aromatic-centered radical anion (1•-) were synthesized through in-situ electron transfer from metal-to-ligand using [IrI] and 2-(2-Pyridylazo)azobenzene (1) in inert hydrocarbon solvent. These are characterized as diradical [IrIII(1•-)2]+[2]+ and monoradical [IrIII(1•-)Cl2(PPh3)] 3. In contrast, a rare metal-mediated hydrolytic cleavage of the C(sp2)-N bond occurred in protic solvent resulting in quaternary radical complex [IrIII(1•-)(1')(PPh3)]+(4)+.
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Physics, University of Malakand, Chakdara, Dir (Lower), 18800, KP, Pakistan.
Context: The structural stability, ground state magnetic order, electronic, elastic and thermoelectric properties of NdMn in the C15, C14 and C36 polytypic phases is investigated. The magnetic phase optimization and magnetic susceptibility reveal that NdMn is antiferromagnetic (AFM) in C36 phase; and paramagnetic (PM) in C14 and C15 phases respectively. The band profiles and electrical resistivity show the metallic nature in all these polytypic phases and reveal that the C36 phase possesses smaller resistivity.
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