94 research outputs found
An algorithm to explore entanglement in small systems
No full textA quantum state’s entanglement across a bipartite cut can be quantified with entanglement entropy or, more generally, Schmidt norms. Using only Schmidt decompositions, we present a simple iterative algorithm to maximize Schmidt norms. Depending on the choice of norm, the optimizing states maximize or minimize entanglement, possibly across several bipartite cuts at the same time and possibly only among states in a specified subspace. Recognizing that convergence but not success is certain, we use the algorithm to explore topics ranging from fermionic reduced density matrices and varieties of pure quantum states to absolutely maximally entangled states and minimal output entropy of channels.</jats:p
Enigmas
No full textArising from the 2020 Darwin College Lectures, this book presents eight essays from prominent public intellectuals on the theme of Enigmas. Each author examines this theme through the lens of their own particular area of expertise, together constituting an illuminating and diverse interdisciplinary volume. Enigmas features contributions by professor of physics Sean M. Carroll, author Jo Marchant, writer and broadcaster Adam Rutherford, professor of earth sciences Tamsin A. Mather, professor of the history of the book Erik Kwakkel, reader in cultural history Tiffany Watt Smith, mathematician and public speaker James Grime, assistant professor of positive AI J. Derek Lomas, and explorer Albert Y.- M. Lin. This volume will appeal to anyone fascinated by puzzles and mysteries, solved and unsolved
Generalized Pauli constraints in large systems: the Pauli principle dominates
No full textLately, there has been a renewed interest in fermionic 1-body reduced density
matrices and their restrictions beyond the Pauli principle. These restrictions
are usually quantified using the polytope of allowed, ordered eigenvalues of
such matrices. Here, we prove this polytope's volume rapidly approaches the
volume predicted by the Pauli principle as the dimension of the 1-body space
grows, and that additional corrections, caused by generalized Pauli
constraints, are of much lower order unless the number of fermions is small.
Indeed, we argue the generalized constraints are most restrictive in
(effective) few-fermion settings with low Hilbert space dimension.Comment: Published version; 37 pages, 5 figure
A Flea on Schrodinger's Cat
No full textContains fulltext :
111305.pdf (Author’s version preprint ) (Open Access
Entropy and Entanglement Bounds for Reduced Density Matrices of Fermionic States
No full textUnlike bosons, fermions always have a non-trivial entanglement. Intuitively, Slater determinantal states should be the least entangled states. To make this intuition precise we investigate entropy and entanglement of fermionic states and prove some extremal and near extremal properties of reduced density matrices of Slater determinantal states
Calculation of the critical temperature of a dilute Bose gas in the Bogoliubov approximation
No full textFollowing an earlier calculation in 3D, we calculate the 2D critical temperature of a dilute, translation-invariant Bose gas using a variational formulation of the Bogoliubov approximation introduced by Critchley and Solomon in 1976. This provides the first analytical calculation of the Kosterlitz-Thouless transition temperature that includes the constant in the logarithm
Quantum spin systems versus Schrodinger operators: A case study in spontaneous symmetry breaking
No full textSpontaneous symmetry breaking (SSB) is mathematically tied to some limit, but must physically occur, approximately, before the limit. Approximate SSB has been independently understood for Schrodinger operators with double well potential in the classical limit [1, 2] and for quantum spin systems in the thermodynamic limit [3, 4]. We relate these to each other in the context of the Curie-Weiss model, establishing a remarkable relationship between this model (for finite N) and a discretized Schrodinger operator with double well potential
Relationship between the time interval from antenatal corticosteroid administration until preterm birth and the occurrence of respiratory morbidity
No full textAbstract not availableFemke F. Wilms, Jolande Y. Vis, Desiree A.P.M. Pattinaja, Rosanna A. Kuin, Monique C. Stam, Janine M. Reuvers, Ben Willem J. Mo
Microstructure of Concentrated Acrylic Dispersions Thickened with Triblock Polymer Surfactants: Studied by Means of Rheometry, Light Scattering and Light Transmission Techniques
No full textThis study has been performed as part of the phenomenology project of Technology Center Waterborne coatings (TCWB) of Akzo Nobel Coatings, with the aim of developing waterborne topcoats with extended open time and improved leveling behavior. Another part of this study has been performed as part of the innovation oriented research program. Innovatie gericht Onderzoek Programma Verf (IOP-Verf), which is focused on aqueous dispersion coatings. The goal of the current study is to investigate the microstructure of concentrated acrylic dispersions thickened with triblock polymer surfactants by means of rheometry, light scattering and light transmission techniques. In this report we have been able to show the microstructure of concentrated acrylic dispersions thickened with triblock polymer surfactants, i.e. Hydrophobically modified ethoxylated urethane (HEUR) thickeners, as a function of the particle volume fraction where two concentration area can be separated: Concentration area I, where still no coalescence takes place; Concentration area II, where coalescence does take place.Applied SciencesChemical Engineering & Material Scienc
The Enigma of Mind: A Theory of Evolution and Conscious Experience
No full textFocusing on human capacity to design, the volume's final chapter draws attention to the fascinating role imagination can play in human life. The relationship between human consciousness and the evolution of the species continues to captivate and puzzle scholars. By revisiting the dialogue between consciousness and evolution, the authors demonstrate how enigmas often necessitate dynamic collaboration between sciences, arts, and humanities. Archaeology provides evidence that the drive for diverse conscious experiences is no new phenomenon, while neuroscience illuminates the ways in which altered states of consciousness can enhance the variety of mental experience. Art, design, and cognitive technologies can build on this picture by providing innovative ways of exploring conscious experience. Inspired by insights from a range of academic disciplines and reflecting on personal experience, this chapter proposes the role of ‘harmony’ as another enigmatic angle of research with potential to shed further light on the functioning both of human society and of the human mind.Design Aesthetic
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