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Showing 1 to 6 of 6 for “"quantum spins"”.
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Quantum spins in semiconductor nanostructures: Hyperfine interactions and optical control
Quantum information technologies offer significantly more computational power for certain tasks and secure communication lines compared to the available classical machines. In recent years there have been numerous proposals for the implementation of quantum computers in several different systems …
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Two topics in non-perturbative lattice field theories : the U(1) quantum link model and perfect actions for scalar theories
… second part we present a new formulation for a quantum field theory with Abelian gauge symmetry. A Hamiltonian is constructed on a four-dimensional Euclidean space-time lattice which is invariant under local transformations. The model is formulated as a 5-dimensional path integral of discrete …
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Quantum Mediated Effective Interactions For Spatially Complex Systems
Magnetic interactions between classical or quantum spin degrees of freedom in a condensed matter system are mediated by particles, which come in two flavors, fermions or bosons. Such a magnetic system can be put on a discrete lattice and one can ask about the nature of the ground state resulting …
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Spectral and dynamical properties of disordered and noisy quantum spin models
… and dynamical characteristics of certain quantum spin systems in the presence of either I) quenched disorder, or II) dynamical noise. In the first part, the quantum random energy model (QREM), a mean-field spin glass model with a many-body localisation transition, is studied. In Chapter 2, …
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Frustrated Magnetism in Strongly Correlated Electron Systems
… induced as a result of magnetic frustration and quantum fluctuations. We show that emergent spin textures can arise close to a magnetic field-induced quantum critical point, when the single magnon excitations have several degenerate non-coplanar minima. In this case, quantum fluctuations can lift …
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Inverse methods in quantum many-body physics
"The interactions of many quantum particles can give rise to fascinating emergent behavior and exotic phases of matter with no classical analogues. Examples include phases with topological properties, which can occur at low temperatures in frustrated magnets and certain superconductors, and …