Results 21 to 30 of about 57,596 (307)
Classical observables from coherent-spin amplitudes
Journal of High Energy Physics, 2021 The quantum field-theoretic approach to classical observables due to Kosower, Maybee and O’Connell provides a rigorous pathway from on-shell scattering amplitudes to classical perturbation theory.
Rafael Aoude, Alexander Ochirov
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A COVARIANT FORMULATION OF CLASSICAL SPINNING PARTICLE [PDF]
Modern Physics Letters A, 1994 Covariantly we reformulate the description of a spinning particle in terms of the Poincaré group. We also construct a Lagrangian which entails all possible constraints explicitly; all constraints can be obtained just from the Lagrangian. Furthermore, in this covariant reformulation, the Lorentz element is to be considered to evolve the momentum or ...
Cho, Jin-Ho +2 more
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Bell's inequalities in the tomographic representation [PDF]
, 2006 The tomographic approach to quantum mechanics is revisited as a direct tool to investigate violation of Bell-like inequalities. Since quantum tomograms are well defined probability distributions, the tomographic approach is emphasized to be the most ...
Man'Ko, Volodya +5 more
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Quantum Brownian motion for magnets
New Journal of Physics, 2022 Spin precession in magnetic materials is commonly modelled with the classical phenomenological Landau–Lifshitz–Gilbert (LLG) equation. Based on a quantized three-dimensional spin + environment Hamiltonian, we here derive a spin operator equation of ...
J Anders, C R J Sait, S A R Horsley
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Decay of spin-spin correlations in disordered quantum and classical spin chains
Physical Review Research, 2020 The real-time dynamics of equal-site correlation functions is studied for one-dimensional spin models with quenched disorder. Focusing on infinite temperature, we present a comparison between the dynamics of models with different quantum numbers S=1/2,1 ...
Jonas Richter +2 more
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Polarizing ³He by Spin Exchange with Potassium [PDF]
, 2004 We present experimental studies on the spin-exchange optical pumping of ³He using alkali metal potassium vapor. High ³He polarizations are achieved using lower laser power than traditional rubidium-³He pumping studies.
Wang, Guodong
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Quantum master equations for spin chemistry [PDF]
, 2021 It is a remarkable fact that the interactions between electron and nuclear spins, and their interactions with a magnetic field, can have a profound effect on chemical reactivity, despite the fact that the characteristic interaction energies are orders of
Fay, Thomas
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Classicality of spin states [PDF]
Physical Review A, 2008 We extend the concept of classicality in quantum optics to spin states. We call a state ``classical'' if its density matrix can be decomposed as a weighted sum of angular momentum coherent states with positive weights. Classical spin states form a convex set C, which we fully characterize for a spin-1/2 and a spin-1.
Giraud, Olivier +2 more
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On quantum and relativistic mechanical analogues in mean field spin models [PDF]
, 2014 Conceptual analogies among statistical mechanics and classical or quantum mechanics often appeared in the literature. For classical two-body mean field models, such an analogy is based on the identification between the free energy of Curie-Weiss type ...
Guerra, F. +10 more
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CLASSICAL RELATIVISTIC SPIN PARTICLES [PDF]
Condensed Matter Physics, 1998 Relativistic spin particles are approached from the stand point of Hamiltonian actions of Poincare group on itself. The several possible solutions are classified and realizations are given in terms of Dirac???s constraints formalism.
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