Isolating electrons on superfluid helium

TL;DR

This paper demonstrates a device that can reliably isolate and control single electrons on superfluid helium across multiple channels, advancing quantum computing qubit technology.

Contribution

It introduces an electron turnstile with parallel channels that achieves electron number quantization, enabling precise electron control for quantum applications.

Findings

Plateau in electron signal indicating quantization

Successful splitting of electron packets

Parallel operation across 78 channels

Abstract

Electrons floating on the surface of superfluid helium have been suggested as promising mobile spin quantum bits (qubits). Transferring electrons extremely efficiently in a narrow channel structure with underlying gates has been demonstrated, showing no transfer error while clocking $10^9$ pixels in a 3-phase charge coupled device (CCD). While on average, one electron per channel was clocked, it is desirable to reliably obtain a single electron per channel. We have designed an electron turnstile consisting of a narrow (0.8$\mu$m) channel and narrow underlying gates (0.5$\mu$m) operating across seventy-eight parallel channels. Initially, we find that more than one electron can be held above the small gates. Underlying gates in the turnstile region allow us to repeatedly split these electron packets. Results show a plateau in the electron signal as a function of the applied gate voltages, indicating quantization of the number of electrons per pixel, simultaneously across the seventy-eight parallel channels.