Entanglement and entropy in electron–electron scattering
Autor: | R. Feder, Peter Schattschneider, H. Gollisch, Stefan Löffler |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
Free electron model
FOS: Physical sciences 02 engineering and technology Quantum entanglement Electron Von Neumann entropy 01 natural sciences Quantum mechanics 0103 physical sciences Entropy (information theory) Physical and Theoretical Chemistry Spectroscopy Physics Quantum Physics Radiation 010304 chemical physics Spins Scattering Physik (inkl. Astronomie) 021001 nanoscience & nanotechnology Condensed Matter Physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials 0210 nano-technology Quantum Physics (quant-ph) Electron scattering |
Popis: | Treating Coulomb scattering of two free electrons in a stationary approach, we explore the momentum and spin entanglement created by the interaction. We show that a particular discretisation provides an estimate of the von Neumann entropy of the one-electron reduced density matrix from the experimentally accessible Shannon entropy. For spinless distinguishable electrons the entropy is sizeable at low energies, indicating strong momentum entanglement, and drops to almost zero at energies of the order of 10 keV when the azimuthal degree of freedom is integrated out, i.e. practically no entanglement and almost pure one-electron states. If spin is taken into account, the entropy for electrons with antiparallel spins should be larger than in the parallel-spin case, since it embodies both momentum and spin entanglement. Surprisingly, this difference, as well as the deviation from the spin-less case, is extremely small for the complete scattering state. Strong spin entanglement can however be obtained by post-selecting states at scattering angle π/2. |
Databáze: | OpenAIRE |
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