CM Theory Seminar | The Redefinition of the SI System of Units, and the Single-Electron Ratchet Pump as a Current Standard

The Systeme Internationale d’Unites is being redefined, in an interesting way. This redefinition has fundamental implications for electrical standards, including standards of current based on the charge of the electron. One mode of semiconducting single-electron pump is the single-gate ratchet mode, based on the concept of a Brownian motor – this fact makes the mode quite subtle in operation. We show experimentally that, in the same devices, we can demonstrate multiple two-gate pumping modes but not the single-gate mode. We propose three mechanisms to explain the lack of plateaus in the single-gate ratchet mode. Educators/textbook writers: I will also discuss a proposal on how to introduce the new SI to students.