Open AccessTwo-site Hubbard-holstein model polaron of quantum entanglement properties
Author(s) -
Xuezao Ren,
Song He,
Cong Hong-Lu,
Wang Xu-Wen
Publication year - 2012
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.61.124207
Subject(s) - von neumann entropy , quantum entanglement , physics , coupling strength , time evolution , quantum mechanics , phonon , hubbard model , quantum , entropy (arrow of time) , polaron , coupling (piping) , von neumann architecture , statistical physics , condensed matter physics , materials science , electron , mathematics , superconductivity , pure mathematics , metallurgy
We obtain the exact solution of energy spectrum and dynamics for the two-site Hubbard-Holstein model by the coherent states orthogonal expansion method. The influences of coupling strength g, the average number of phonons n and the initial electronic state on the evolution of system entanglement and von Neumann entropy are discussed. Numerical results are as follows. (a) Entanglement evolution with time shows a good periodicity. When the other parameters are fixed, the evolution period decreases as the coupling strength g goes up but it is independent of the average number of phonons n. (b) The von Neumann entropy of the system demonstrates strict synchronia with the electronic state occupancy probability. (c) Under the weak coupling strength and low average number of phonons, the initial electronic state c2+ c2+|Oe or c1+ c1+|Oe shows larger maximum von Neumann entropy during its evolution than that of c1+c2+c1+c2++ but they gradually approach to each other with the increase of coupling strength or average number of phonons.