arXiv:cond-mat/9705191

Response to Greiter's Comment

Eugene Demler, Shoucheng Zhang, Stefan Meixner, Werner R. Hanke

Published May 20, 1997• 0 citations

Abstract

Greiter claimed erroneously that the pi-excitation of the Hubbard model has an energy of the order of U. This mistake originates from a inconsistent treatment of the two particle Hartree energy and the Hartee correction to the chemical potential. In any self-consistent calculations, these two contributions cancel exactly, as shown by Kohn, Luttinger and Ward. We also show that his interpretation of the finite-size studies is inconsistent.

DOI: 10.48550/arxiv.cond-mat/9705191

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In a comment on my recent manuscript on the pi-particle [cond-mat/9705049], Demler et al. [cond-mat/9705191] argued that there is a correction to the chemical potential which enters the expression for the energy of the pi-particle given in [Demler and Zhang, Phys. Rev. Lett. 77, 4126 (1995)]. This is shown to be incorrect. I further offer an interpretation for the low-energy resonances observed by Meixner et al. [cond-mat/9701217] in the pi-pi correlation function in a finite-size Hubbard cluster at low electron densities.

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