專題演講

2018/09/28(Fri)     14:00 -15:00    5th Floor(1st meeting room)

Title

Tunable SQUIDs using graphene Josephson junctions

Speaker

Dr. Michael Thompson

Department of Physics, Lancaster University

Abstract

Conventional superconducting quantum interference devices (SQUIDs) are amongst the most sensitive magnetometers in widespread use and can be operated at convenient temperatures for cooling with liquid helium or nitrogen. Recent work has seen the development of new superconducting interference devices that exploit the superconducting proximity effect, such as HyQUIDs [1], SQUIPTs [2] and graphene junction SQUIDs [3]. These devices have the potential to outperform traditional SQUID magnetometers in their sensitivity and flexibility.

We investigate the properties of SQUIDs that incorporate ballistic graphene Josephson junctions and determine their suitability as sensitive magnetometers. Each junction of the SQUID can be individually controlled using a local field effect gate. Using these gates, the SQUID junction critical currents can be modified individually, allowing the sensitivity and symmetry of the SQUID to be controlled in-situ. Such tunable junctions have the potential to add functionality to existing technologies; for example, to make SQUID magnetometers with tunable sensitivity or superconducting qubits with fast electrical control.【Please see attached file for details.】

【Remark】
In the spirit of future collaboration, Prof. Richard Haley, as the Director of Research for Lancaster Physics, will give a 15 min introduction to their research facilities and capabilities. (paper)