Particle-hole symmetry of charge excitation spectra in the paramagnetic phase of the Hubbard model

Vu Hung Dao; Raymond Frésard

doi:10.12693/aphyspola.133.336

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arXiv · 1708.07760

Particle-hole symmetry of charge excitation spectra in the paramagnetic phase of the Hubbard model

Vu Hung Dao·Raymond Frésard

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Abstract

The Kotliar and Ruckenstein slave-boson representation of the Hubbard model allows to obtain an approximation of the charge dynamical response function resulting from the Gaussian fluctuations around the paramagnetic saddle-point in analytical form. Numerical evaluation in the thermodynamical limit yields charge excitation spectra consisting of a continuum, a gapless collective mode with anisotropic zero-sound velocity, and a correlation induced high-frequency mode at $ω\approx U$. In this work we show that this analytical expression obeys the particle-hole symmetry of the model on any bipartite lattice with one atom in the unit cell. Other formal aspects of the approach are also addressed.

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Vu Hung Dao, Raymond Frésard. 2017-09-29. Particle-hole symmetry of charge excitation spectra in the paramagnetic phase of the Hubbard model. https://doi.org/10.12693/aphyspola.133.336

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