Photon assisted tunneling as an origin of the Dynes density of states

TL;DR

This paper demonstrates that environmental effects, modeled as photon-assisted tunneling, can produce a Dynes-like density of states in superconductor tunnel junctions, impacting device performance.

Contribution

It introduces a theoretical framework linking high-temperature environment effects to the Dynes DOS, supported by experimental validation, and applies this to enhance single-electron turnstile operation.

Findings

High-temperature environments induce a Dynes-like DOS in superconductor junctions.

Experimental data supports the photon-assisted tunneling model.

Improved single-electron turnstile performance achieved.

Abstract

We show that the effect of a high-temperature environment in current transport through a normal metal-insulator-superconductor tunnel junction can be described by an effective density of states (DOS) in the superconductor. In the limit of a resistive low-ohmic environment, this DOS reduces into the well-known Dynes form. Our theoretical result is supported by experiments in engineered environments. We apply our findings to improve the performance of a single-electron turnstile, a potential candidate for a metrological current source.