Modeling Bloch Oscillations in Nanoscale Josephson Junctions

Published

August 7, 2017

Author(s)

Heli C. Vora, Richard Kautz, Sae Woo Nam, Jose A. Aumentado

Abstract

Bloch oscillations in nanoscale Josephson junctions with a Coulomb charging energy comparable to the Josephson coupling energy are explored within the context of a model previously considered by Geigenmüller and Schön that includes Zener tunneling and treats quasiparticle tunneling as an explicit shot-noise process. The dynamics of the junction quasicharge are investigated numerically using both Monte-Carlo and ensemble approaches to calculate voltage--current characteristics in the presence of microwaves. We examine in detail the origin of harmonic and subharmonic Bloch steps at dc biases I=(n/m)ef induced by microwaves of frequency f and consider the optimum parameters for the observation of harmonic (m=1) steps. We also demonstrate that the GS model allows a detailed semi-quantitative fit to experimental voltage--current characteristics previously obtained at the Chalmers Institute of Technology, confirming and strengthening the interpretation of the observed microwave-induced steps in terms of Bloch oscillations.

Citation

Physical Review B

Volume

96

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevB.96.054505

Keywords

Josephson Junctions, Bloch Oscillations, Coulomb Blockade, Current Standard, Tunneling, Superconductivity

Citation

Vora, H. , Kautz, R. , Nam, S. and Aumentado, J. (2017), Modeling Bloch Oscillations in Nanoscale Josephson Junctions, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.96.054505 (Accessed December 17, 2024)