Towards A Single Electron Current On Superfluid Helium

The aim of this dissertation was to investigate the application of a system of electrons floating above the surface of superfluid helium to the field of single electron transport. Previous work done by Dr Forrest Bradbury at Princeton University (now a collaborator in the group) demonstrated the highly efficient and precise control of packets of electrons floating on the surface of superfluid helium, localised to channels defined in a silicon substrate. Using similar devices and methodologies, the work done in this dissertation investigates whether this modality of electron transport can be effectively applied to deliver a current of single electrons. Single electron devices have numerous applications in the field of metrology and quantum information processing. They allow for measurements to be made of fundamental quantities, such as the charge of an electron, and further demonstrate various quantum mechanical properties of nature. Presented in this dissertation is the work completed to date, which includes: the design and fabrication of the nanoscale device used to conduct the electrons on superfluid helium experiments, the required electronics needed to control the device and the data acquisition system needed to read various signals off the device. The fabrication was done at Oak Ridge National Labs in the USA. Additionally, a hermetically sealed superfluid cell designed in collaboration with Dr Jay Amrit from Universit´e Paris-Sud, France used to house the device is presented, as well the probe needed to insert this cell into the dilution fridge. The theory behind the functionality of the device and the way in which it would work is developed. A simulation of working of the device is presented, as well as the expected measurement quantities. The outlook for continued work in this exciting and very novel physical system is also presented.

Grantor

Department of Electrical Engineering

Year dc:date.issued

2021

Author dc:creator

• Funk, Oliver

Advisors dc:contributor.advisor

• Blumenthal, Mark
• Nicolls, Frederick

• Electrical Engineering

Handle dc:identifier.uri

http://hdl.handle.net/11427/35733

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/35733