1. Engineering Department; Lancaster University; Lancaster LA1 4YR UK
2. Quantum Technology Centre; Department of Physics; University of Lancaster; Lancaster LA1 4YW UK
3. Advanced Technology Institute; Electronic and Electrical Engineering; University of Surrey; Guildford GU2 7HX UK
4. Department of Engineering; University of Cambridge; 9 JJ Thomson Avenue Cambridge CB3 0FA UK
5. Quantum Nanoelectronics Research Center (QNERC); Tokyo Institute of Technology; 2-12-1 Ookayama Meguro-ku Tokyo 152-8550 Japan