A gapless charge mode induced by the boundary states in the half-filled Hubbard open-chain

Abstract

We discuss the ground state and some excited states of the half-filled Hubbard model defined on an open chain with L sites, where only one of the boundary sites has a different value of chemical potential. We consider the case when the boundary site has a negative chemical potential -p and the Hubbard coupling U is positive. By an analytic method we show that when p is larger than the transfer integral some of the ground-state solutions of the Bethe ansatz equations become complex-valued. It follows that there is a ``surface phase transition'' at some critical value p_c; when p<p_c all the charge excitations have the gap for the half-filled band, while there exists a massless charge mode when p>p_c.

Revtex, 25 pages, 3 eps figures; Full revision with Appendixes added

References in corpus (4)

• Spectrum of boundary states in the open Hubbard chain
• X-ray edge singularity in integrable lattice models of correlated electrons
• Boundary bound states for the open Hubbard chain with boundary fields
• Magnetic susceptibility and low-temperature specific-heat of integrable 1-D Hubbard model under open-boundary conditions

Cited by in corpus (7)

• Breakdown of a Mott insulator -- non-adiabatic tunneling mechanism
• General boundary conditions for the sl(N) and sl(M|N) open spin chains
• Topological quantum phase transition in the BEC-BCS crossover phenomena
• Determination of Boundary Scattering, Intermagnon Scattering, and the Haldane Gap in Heisenberg Chains
• Non-regular eigenstate of the XXX model as some limit of the Bethe state
• Integrable open boundary conditions for the Bariev model of three coupled XY spin chains
• Strong zero modes in integrable spin-S chains