Dissipation in quantum tunnel junctions

TL;DR

This paper models energy dissipation in quantum tunneling within solid-state junctions, revealing how temperature and voltage influence dissipation and identifying a critical temperature of 137 K where dissipation behavior changes.

Contribution

It introduces a nonlinear friction-based model fitted to experimental data to analyze dissipation in quantum tunneling, highlighting temperature-dependent effects and a critical temperature for dissipation behavior.

Findings

Dissipation decreases with increasing particle energy at fixed temperature.

A critical temperature of 137 K marks a change in dissipation characteristics.

Dissipation parameters {3} and {b} vary linearly above 137 K.

Abstract

Based on experimental data, we propose a model to evaluate the energy dissipated during quantum tunneling processes in solid-state junctions. This model incorporates a nonlinear friction force expressed in the general form f(x)={\gamma} v(x)^{\alpha}, where {\gamma} is the frictional coefficient, which is fitted to data. We study this by applying voltages just below the barrier height up to near break down voltages. Furthermore, by lowering the temperature and adjusting the applied voltage to the junction, the effect on dissipation caused by the variation in barrier height is examined. We underline that the crucial dependency of dissipation on the fraction of particle energy lost is modulated by two primary mechanisms: the application of voltage and the variation of temperature. The fraction of energy dissipated decreases in general for increasing energies of the tunneling particles at a given temperature. However, for a given energy of the tunneling particle, the present work demonstrates a turning point at a temperature of 137 K, after which the dissipated energy starts increasing for higher temperatures. The latter can possibly be due to the increase of electron-phonon interactions which become predominant over barrier height reduction at higher temperatures and hence we identify T = 137 K as a critical temperature for change in dissipative characteristics of the solid-state junction under consideration. Notably, also the study identifies significant changes in dissipation parameters, {\gamma} and {\alpha}, above 137 K, exhibiting a linear decline and underscoring the importance of further research at higher temperatures.