Greiter replies to Demler, Zhang, Meixner, and Hanke

TL;DR

This paper refutes a correction proposed by Demler et al. to the pi-particle energy expression and offers an interpretation for low-energy resonances observed in pi-pi correlations in a Hubbard cluster.

Contribution

It clarifies the incorrectness of Demler et al.'s proposed correction and provides an interpretation for experimental low-energy resonances in a specific Hubbard model context.

Findings

Demler et al.'s correction is shown to be incorrect.

Provides an interpretation for low-energy resonances in Hubbard clusters.

Clarifies the theoretical understanding of pi-particle energies.

Abstract

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.