Demonstration of dual Shapiro steps in small Josephson junctions.

ABSTRACT: Bloch oscillations in small Josephson junctions were predicted theoretically as the quantum dual to Josephson oscillations. A significant consequence of this prediction is the emergence of quantized current steps, so-called dual Shapiro steps, when synchronizing Bloch oscillations to an external microwave signal. These steps potentially enable a fundamental standard of current I, defined via the frequency f of the external signal and the elementary charge e, I = ± n × 2ef, where n is a natural number. Here, we realize this fundamental relation by synchronizing the Bloch oscillations in small Al/AlO_x/Al Josephson junctions to sinusoidal drives with frequencies from 1 to 6 GHz and observe dual Shapiro steps up to I ≈ 3 nA. Inspired by today's voltage standards and to further confi

SUBMITTER: Kaap F 

PROVIDER: S-EPMC11461542 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature