Low-energy local density of states of the 1D Hubbard model

¹ Department of Physics and Research Center OPTIMAS, University of Kaiserslautern D-67663 Kaiserslautern, Germany, EU
² Graduate School of Excellence Material Science in Mainz
³ Institut für Theoretische Physik, University of Dresden - D-01062 Dresden, Germany, EU

Received: 19 November 2012
Accepted: 15 February 2013

Abstract

We examine the local density of states (DOS) at low energies numerically and analytically for the Hubbard model in one dimension. The eigenstates represent separate spin and charge excitations with a remarkably rich structure of the local DOS in space and energy. The results predict signatures of strongly correlated excitations in the tunneling probability along finite quantum wires, such as carbon nanotubes, atomic chains or semiconductor wires in scanning tunneling spectroscopy (STS) experiments. However, the detailed signatures can only be partly explained by standard Luttinger liquid theory. In particular, we find that the effective boundary exponent can be negative in finite wires, which leads to an increase of the local DOS near the edges in contrast to the established behavior in the thermodynamic limit.