Energy dissipation in macroscopic tunnel junctions

Tunnel junctions constitute a remarkable research area due to their potential applications in information storage systems and quantum computing. Tunneling currents research projects can cover the study of superconducting, magnetic or spintronic devices. Most of these devices have a tunnel barrier that can be theoretically studied with Simmons model for low or intermediate voltages. However, fitting experimental data for high voltages can be challenging for some devices. One of the reasons for this theory to not agree with experimental data is that energy dissipation in the tunnel barrier is often neglected. In this work, we show an I-V characterization of a macroscopical high quality tunnel junction of the form Al/Al2O3/Al and its deviation with the theoretical Simmons model for certain voltages. We include a dissipation factor with a friction coefficient, η, as it is included in previous works for the study of tunneling times. Results show that the friction coefficient depends on the voltage, which implies that less energy is lost in the process of tunneling when the incident energy of the particle is reaching the height of the barrier.