Suppression of back-tunnelling events in hybrid single-electron turnstiles by source-drain bias modulation

Abstract

Accuracy of single-electron currents produced in hybrid turnstiles at high operation frequencies is, among other errors, limited by electrons tunnelling in the wrong direction. Increasing the barrier transparency between the island and the leads, and the source-drain bias helps to suppress these events in a larger frequency range, although they lead to some additional errors. We experimentally demonstrate a driving scheme that suppresses tunnelling in the wrong direction hence extending the range of frequencies for generating accurate single-electron currents. The main feature of this approach is an additional AC signal applied to the bias with twice the frequency as the one applied to the gate electrode. This allows additional modulation of the island chemical potential. By using the new approach under certain parameters, we improve the single-electron current accuracy by one order of magnitude. Finally, we show through experimentally-contrasted calculations that our method can improve accuracy even in devices for which the usual gate driving gives errors $\sim 10^{-3}$ at high frequencies and can bring them under $5\times 10^{-4}$.

11 pages

References in corpus (10)

• Non-adiabadic charge pumping in a hybrid SET transistor
• Andreev Current-Induced Dissipation in a Hybrid Superconducting Tunnel Junction
• Parity effect in superconducting aluminum single electron transistors with spatial gap profile controlled by film thickness
• Environmentally Activated Tunneling Events in a Hybrid Single-Electron Box
• Active quasiparticle suppression in a non-equilibrium superconductor
• A random-walk benchmark for single-electron circuits
• Frequency to power conversion by an electron turnstile
• Ultimate accuracy of frequency to power conversion by single-electron injection
• Recovery of a SINIS turnstile accuracy in a strongly non-equilibrium regime
• Zero-average bias bidirectional single-electron current generation in a hybrid turnstile