Spectral function of a quarter-filled one-dimensional charge density wave insulator.

We consider a one-dimensional charge density wave insulator formed by umklapp processes in a quarter-filled band. The spectrum of the model consists of gapless, uncharged excitations carrying spin +/- 1/2 (spinons) and gapped, spinless excitations carrying charge -/+ signe/2 (solitons and antisolitons). We calculate the low-energy behavior of the single-electron Green's function at zero temperature. The spectral function exhibits a featureless scattering continuum of two solitons and many spinons. The theory predicts that the gap observed by angle resolved photoemission is twice the activation gap in the dc conductivity. We comment on possible applications to PrBa(2)Cu(3)O(7) and to the Bechgaard salts

Higher conservation laws and algebraic Bethe Ansa-umltze for the supersymmetric t-J model.

We construct the enveloping fundamental spin model of the t-J Hamiltonian using the quantum-inverse-scattering method (QISM), and present all three possible algebraic Bethe Ansa$iuml-tze. Two of the solutions have been previously obtained in the framework of the coordinate-space Bethe Ansatz by Sutherland and by Schlottmann and Lai, whereas the third solution is new. The formulation of the model in terms of the QISM enables us to derive explicit expressions for higher conservation laws. © 1992 The American Physical Society

Essler, Korepin, and Schoutens reply.

A reply to the comment by Antimo Angelucci and Sandro Sorella on Original: Fabian H. Essler, Vladimir E. Korepin, and Kareljan Schoutens, Electronic model for superconductivity, Phys. Rev. Lett. 70, 73 (1993

Complete solution of the one-dimensional Hubbard model.

We show how to construct a complete set of eigenstates of the Hamiltonian of the one-dimensional Hubbard model on a finite lattice of even length L. This is done by using the nested Bethe ansatz and the SO(4) symmetry of the model. © 1991 The American Physical Society