Current-voltage characteristics of a tunnel junction with resonant centers

TL;DR

This paper models the current-voltage behavior of a tunnel junction with impurities, revealing how Coulomb interactions and temperature influence the I-V characteristics, especially the slope changes at specific voltages.

Contribution

It introduces a detailed calculation of I-V characteristics considering Coulomb repulsion and resonant tunneling in impurity-containing junctions, highlighting temperature effects.

Findings

Linear I-V at low temperatures with slope change at E_c

Ohmic behavior at temperatures comparable to E_c

Charging energy E_c influences the spectrum of impurity electrons

Abstract

We calculate the I-V characteristics of a tunnel junction containing impurities in the barrier. We consider the indirect resonant tunneling involving the impurities. The Coulomb repulsion energy $E_c$ between two electrons with opposite spins simultaneously residing on the impurity is introduced by an Anderson Hamiltonian. At low temperatures $T \ll E_c$ the I-V characteristic is linear in $V$ both for $V<E_c$ and for $V>E_c$ and changes slope at $V=E_c$. This behavior reflects the energy spectrum of the impurity electrons - the finite value of the charging energy $E_c$. At $T \sim E_c$ the junction reveals an ohmic-like behavior as a result of the smearing out of the charging effects by the thermal fluctuations.