Bosonization of strongly interacting electrons

TL;DR

This paper develops a comprehensive bosonization approach for strongly interacting one-dimensional electrons, valid across a broad energy range, and calculates spectral functions revealing new features at energies between J and E_F.

Contribution

It introduces a novel theoretical method combining charge bosonization with exact spin treatment, extending analysis beyond the low-energy regime of traditional models.

Findings

Spectral functions show a strong peak at k=0.

Analytical description of spectral singularities near 3k_F.

Method applicable at all energies below E_F, including J to E_F range.

Abstract

Strong repulsive interactions in a one-dimensional electron system suppress the exchange coupling J of electron spins to a value much smaller than the Fermi energy E_F. The conventional theoretical description of such systems based on the bosonization approach and the concept of Tomonaga-Luttinger liquid is applicable only at energies below J. In this paper we develop a theoretical approach valid at all energies below the Fermi energy, including a broad range of energies between J and E_F. The method involves bosonization of the charge degrees of freedom, while the spin excitations are treated exactly. We use this technique to calculate the spectral functions of strongly interacting electron systems at energies in the range J<<epsilon<< E_F$. We show that in addition to the expected features at the wavevector k near the Fermi point k_F, the spectral function has a strong peak centered at k=0. Our theory also provides analytical description of the spectral function singularities near 3k_F (the "shadow band" features).