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arXiv · 2206.10408

Density matrix of electrons coupled to phonons and the electron-phonon entanglement content of excited states

Gergő Roósz·Karsten Held
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Abstract

We derive the exact reduced density matrix for the electrons in an analytically solvable electron-phonon model. Here, the electrons are described as a Luttinger liquid that is coupled to Einstein phonons. We further derive analytical expressions for the electron-phonon entanglement, its spectrum and mutual information at finite and zero temperature as well as for excited states. The entanglement entropy is additive in momentum for the quasi-particle excited states, but not in the electron-phonon coupled eigenmodes of the system.

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Gergő Roósz, Karsten Held. 2022-06-21. Density matrix of electrons coupled to phonons and the electron-phonon entanglement content of excited states. https://doi.org/10.1103/physrevb.106.195404

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