Ultra-Low Noise Measurement Capability for Quantum Science

Lead Research Organisation: University College London
Department Name: Electronic and Electrical Engineering

Abstract

In the past few years there has been a very high international interest in Quantum Physics leading to new Technologies. The success of these technologies will lead to advances in a range of activities including new types of sensor, secure communications and advanced computing with the ability to perform calculations not presently possible. This latter category is based on the properties of quantum systems to develop bits, so called qu-bits, which can take any value between 0 and 1 unlike present, conventional, bits which are 0 or 1. However the development of this technology requires many advances in techniques and understanding, particularly as the means of generating the qubits are extremely low energy requiring temperatures very close to the absolute zero. Commercial equipment is available for reaching these temperatures but often electronic noise emanating from other equipment, radio stations and other sources is picked up by the device under test. This prevents the electrons from reaching the lowest temperatures necessary to observe the quantum effects. It is the purpose of this grant to develop noise reduction techniques in this very low temperature equipment which enables investigation of quantum properties including those not presently observable. The effects which we hope to investigate include some which stem from the repulsion of electrons in specific devices forming a new type of configuration and behaving as if they had a fractional charge. Other effects are based on quantum entanglement, which has no non-quantum counterpart, and arises from the property of two electrons to sense each other and mutually change their properties even when apart. To observe these effects requires a very detailed and precise isolation of the elecrons from any disturbing influences at extremly low temperatures and it is the purpose of this application to establish this isolation and investigate the new quantum properties which may emerge.

Publications

10 25 50
 
Description Unfortunately there was a delay in delivery of the equipment due to the sample probe not reaching the guaranteed low temperature. This problem was solved but then we had an issue with the room layout and the only area which had a sufficiently high ceiling did not have an adequate supply of water cooling. This has now been rectified and key measurements will start shortly, this experience illustrates that the attainment of ultra low temperatures for quantum measurements requires considerable supporting infrastructure.
As a result of the above and the Covid induced delay UKRI/EPSRC granted us a year's extension so we can adequately complete the grant. The equipment will be a valuable addition to the quantum work at UCL.
Exploitation Route The equipment will be made available to other groups in UCL and within the UK. As part of our collaboration with the University of California, Santa Barbara, we will measure samples made there. Depending on their staffing position a person from Santa Barbara may come to the UK to participate in measurements.
Sectors Aerospace

Defence and Marine

Digital/Communication/Information Technologies (including Software)

Electronics