STM tunneling through a quantum wire with a side-attached impurity

TL;DR

This paper investigates how a side-attached impurity affects STM tunneling in a quantum wire, revealing significant modifications to local density of states and transport properties based on impurity coupling and wire length.

Contribution

It introduces a detailed analysis of impurity effects on STM tunneling in quantum wires using a tight-binding and nonequilibrium Green function approach, highlighting the impurity's influence.

Findings

Impurity presence alters local density of states significantly.

Coupling strength and wire length impact impurity transport properties.

STM differential conductance reflects impurity and coupling effects.

Abstract

The STM tunneling through a quantum wire (QW) with a side-attached impurity (atom, island) is investigated using a tight-binding model and the nonequilibrium Keldysh Green function method. The impurity can be coupled to one or more QW atoms. The presence of the impurity strongly modifies the local density of states of the wire atoms, thus influences the STM tunneling through all the wire atoms. The transport properties of the impurity itself are also investigated mainly as a function of the wire length and the way it is coupled to the wire. It is shown that the properties of the impurity itself and the way it is coupled to the wire strongly influence the STM tunneling which is reflected in the density of states and differential conductance.