Dr Jonathan PranceLecturer
My research concerns the low temperature properties of nanoscale structures. In particular, quantum dots, graphene and 2D materials, superconducting devices, and nanomechanical resonators. At low enough temperatures, quantum mechanical phenomena dominate the behaviour of these systems. I am interested in how this can be exploited to build new solid-state devices to advance computation, metrology, and sensing. I am currently working on techniques to reach temperatures below 1 millikelvin inside nanoscale devices.
PhD Supervision Interests
Ultralow temperatures in nanoelectronic devices The ability to cool materials to millikelvin temperatures has been the foundation of many breakthroughs in condensed matter physics and nanotechnology. At this frontier, quantum behaviour can be studied by making devices smaller and colder, increasing coherence across the system. The goal of this project is to apply a new technique – on-chip demagnetisation refrigeration – to reach temperatures below 1 millikelvin in nanoelectronic structures. This will open a new temperature range for nanoscale physics. As experiments are pushed into the sub-millikelvin regime, it becomes increasingly difficult to measure and define the temperature of a material or device. The thermal coupling between various sub-systems in can be extremely small; for example, the electrons in the metal wires contacting an on-chip structure can be at a different temperature to the electrons in the chip, the phonons in the chip, and the apparatus that you are using to cool it. This situation calls for a variety of thermometry techniques, each suited to measuring the temperature of a different physical system. The thermometers must also have extremely low heat dissipation and excellent isolation from the room temperature environment. This project will include the development of new and existing thermometry techniques that are suitable for sub-millikelvin temperatures. Devices will be produced in the Lancaster Quantum Technology Centre cleanroom, and by our collaborators. Experiments will be conducted using the cutting-edge facilities of the Ultralow Temperature Physics group at Lancaster. 2D materials in low temperature, isolated environments Graphene and other 2D materials can be used to build coherent electronic devices such as Superconducting Quantum Interference Devices (SQUIDs) and Quantum dots. These devices can be used as sensors with the ability to detect single quanta of charge and magnetic flux. In order to reach this limit, it is necessary to cool the devices into the millikelvin regime and to isolate them from unwanted external perturbations including varying magnetic fields, electric fields and mechanical vibration. In this project, the recently completed IsoLab facility at Lancaster will provide the “quiet” environment to study quantum devices made from 2D materials and to assess their performance as sensors. IsoLab is a new facility that provides three highly-isolated laboratories for testing the electrical, mechanical and optical properties of materials and devices. One of the three laboratories is equipped with a dilution refrigerator capable of cooling samples below 10 millikelvin. The refrigerator is housed in an electromagnetically shielded room and rests on a 50-tonne concrete block to provide vibration isolation. As well as studying new devices, this project will also include testing and development of the IsoLab environment. A student working on this project will learn how to design and fabricate nanoelectronic devices and study their electrical characteristics at low temperature. The student will join an ongoing collaboration between Lancaster and the National Graphene Institute in Manchester to study graphene/superconductor hybrid devices.
Selected Publications Show all 29 publications
Edge currents shunt the insulating bulk in gapped graphene
Zhu, M.J., Kretinin, A.V., Thompson, M.D., Bandurin, D.A., Hu, S., Yu, G.L., Birkbeck, J., Mishchenko, A., Vera-Marun, I.J., Watanabe, K., Taniguchi, T., Polini, M., Prance, J.R., Novoselov, K.S., Geim, A.K., Ben Shalom, M. 17/02/2017 In: Nature Communications. 8, 6 p.
Nanoelectronic primary thermometry below 4 mK
Bradley, D.I., George, R.E., Gunnarsson, D., Haley, R.P., Heikkinen, H., Pashkin, Y., Penttilä, J., Prance, J.R., Prunnila, M., Roschier, L., Sarsby, M. 27/01/2016 In: Nature Communications. 7, 6 p.
Quantum oscillations of the critical current and high-field superconducting proximity in ballistic graphene
Ben Shalom, M., Zhu, M.J., Fal'ko, V.I., Mishchenko, A., Kretinin, A.V., Novoselov, K.S., Woods, C.R., Watanabe, K., Taniguchi, T., Geim, A.K., Prance, J.R. 04/2016 In: Nature Physics. 12, 4, 5 p.
Electronic Refrigeration of a Two-Dimensional Electron Gas
Prance, J.R., Smith, C.G., Griffiths, J.P., Chorley, S.J., Anderson, D., Jones, G.A.C., Farrer, I., Ritchie, D.A. 10/04/2009 In: Physical Review Letters. 102, 14, p. -. 4 p.
Quantum control and process tomography of a semiconductor quantum dot hybrid qubit
Kim, D., Shi, Z., Simmons, C.B., Ward, D.R., Prance, J., Koh, T.S., Gamble, J.K., Savage, D.E., Lagally, M.G., Friesen, M., Coppersmith, S.N., Eriksson, M.A. 3/07/2014 In: Nature. 511, 7508, 5 p.
Single-Shot Measurement of Triplet-Singlet Relaxation in a Si/SiGe Double Quantum Dot
Prance, J.R., Shi, Z., Simmons, C.B., Savage, D.E., Lagally, M.G., Schreiber, L.R., Vandersypen, L.M.K., Friesen, M., Joynt, R., Coppersmith, S.N., Eriksson, M.A. 26/01/2012 In: Physical Review Letters. 108, 4, p. -. 4 p.
Ultralow temperature thermometry with nanoscale devices
01/07/2016 → …
01/04/2016 → …
Development of Cryofree Ultra Low Temperature Environment for Quantum Enhanced Sensors
01/05/2015 → …
01/08/2013 → …