Counting Individual Electrons on Liquid Helium

TL;DR

This paper demonstrates trapping and detecting individual electrons on superfluid helium using microfabricated electrodes and a superconducting SET, paving the way for scalable quantum computing architectures.

Contribution

It introduces a novel electrostatic trap for single electrons on helium and a detection method using a superconducting SET, enabling scalable quantum information processing.

Findings

Successful trapping of single electrons on helium surface.

Detection of electrons via Coulomb staircase with SET.

Potential design for scalable quantum processor.

Abstract

We show that small numbers of electrons, including a single electron, can be held in a novel electrostatic trap above the surface of superfluid helium. A potential well is created using microfabricated electrodes in a 5 micron diameter pool of helium. Electrons are injected into the trap from an electron reservoir on a helium microchannel. They are individually detected using a superconducting single-electron transistor (SET) as an electrometer. A Coulomb staircase is observed as electrons leave the trap one-by-one until the trap is empty. A design for a scalable quantum information processor using arrays of electron traps is presented