Tunneling singularities in the open Hubbard chain

TL;DR

This paper investigates tunneling singularities in a one-dimensional Hubbard chain, revealing how boundary conditions and electron interactions influence the I-V characteristics near resonant levels.

Contribution

It provides an exact theoretical analysis of tunneling singularities in the Hubbard model using boundary conformal field theory and boundary fields.

Findings

Identification of singularity exponents as a function of system parameters

Prediction of multiple singularities for boundary potentials with bound states

Analytical results applicable to quantum dot tunneling in 1D systems

Abstract

We study singularities in the I-V characteristics for sequential tunneling from resonant localized levels (e.g. a quantum dot) into a one dimensional electron system described by a Hubbard model. Boundary conformal field theory together with the exact solution of the Hubbard model subject to boundary fields allows to compute the exponents describing the singularity arising when the energy of the local level is tuned through the Fermi energy of the wire as a function of electron density and magnetic field. For boundary potentials with bound states a sequence of such singularities can be observed.