"in vivo" Modification of Superconducting Quantum Electronic Circuits

The award funds a unique cryogenic nanofabrication tool with superior imaging capability and the possibility to modify quantum circuitry "in vivo". Based on the Zeiss ORION Nanaofabrication tool combined with innovative cryogenics in the few-Kelvin regime, the tool enables superconducting quantum circuitry to be modified in-situ with a focussed ion beam of Neon, allowing precision tailoring of component values and testing with radio frequency and DC probes in the superconducting state without the need to break vacuum. Such a prospect hugely enhances the potential for rapid development of prototype quantum devices and the quality with which they are selected for further testing, for example for further testing at milliKelvin temperatures or for commercial use. The imaging capabilities of the He-ion microscope will in addition support the recently funded world-class electron-beam-lithography system, the integrated tool being able to image and modify features of size less than 5 nm with 0.1 nm resolution while in the superconducting state.

Superconducting Quantum Technology is regarded worldwide as one of the key underpinning technologies for the construction of a quantum computer and for novel sensing and metrology applications.
Based on fabrication techniques used in semi-conductor processing, the creation of electrical circuits that operate according to the laws of quantum physics is astonishing in that the devices are the first man made objects (as opposed to natural entities such as atoms, electrons and photons) to display quantum effects. They are all the more fantastic because of their ability to be modified by design or construction in ways that naturally quantum objects cannot. As quantum electrical (qubit) circuits, they hold the potential to solve all of the problems of addressability, controllability, controlled qubit coupling and readout that many other architectures based on natural quantum objects find difficult. Major corporations such as Google, IBM and Raytheon are now investing in this field. The exploration and exploitation of a new generation of Superconducting Quantum Circuits including quantum meta-materials, coherent quantum phase slip (with consequent potential for a redefinition of the unit of electrical current, the Ampere), microwave quantum optics and quantum limited amplification as well as further development of multi-qubit devices are also key objectives of our research.

The new tool will be installed in the new nanofabrication facility at Royal Holloway, part of a UK Centre for Superconducting and hybrid Quantum Systems collaboration. We will build on our strong collaborations with the National Physical Laboratory and Lancaster University in a consortium that can offer Superconducting Quantum Circuit nanofabrication facilities to UK academics the field free of access charges. We were the first group in the UK to successfully establish a superconducting qubit foundry and we will build on our state-of-the-art capability with the aim of providing a streamlined route from science to technology. The new facility opens in summer 2018 and is also strongly involved in providing commercial superconducting device nanofabrication services. Our overall aim is to establish the UK as a world leader in superconducting quantum technology.

Superconducting quantum systems are recognised world-wide to provide a compelling route to new disruptive technologies. Multinationals IBM, Google, Lockheed Martin, Raytheon and others are funding significant commercial efforts to develop superconducting quantum computing with already operational multi-qubit prototypes. Beyond this there is much broader potential for very strong impacts in instrument development, quantum sensing and metrology.

Consortium research expertise includes quantum limited amplification and non-linear bifurcation amplifiers (Meeson), coherent quantum phase slip, artificial atom physics, microwave quantum optics (Astafiev); hybrid devices including the commercially important HyQUID (Petrashov); nanofabrication (Antonov and Shaikhaidarov, RHUL, Pashkin, Lancaster); qubit physics and technology (Astafiev and Pashkin) and world-class expertise in metrology (NPL). Consequently we envisage a broad impact of academic research advances and commercial exploitation.

The requested equipment combines two advanced technologies in cryogenics and nanofabrication to develop a unique tool capable of highly disruptive impact in the approach to the development of the superconducting technology. These advances will drive device innovation, speeding up development times and exploiting, for example, advanced materials with < 5nm features. Development of this tool will have worldwide impact through IP licenses to Zeiss for commercial exploitation.

The RHUL invented HyQUID device is licensed and being used in an innovative MEG medical tool marketed by York Instruments, four scanners are already sold worldwide. We expect to exploit this opportunity further by testing device limits in terms of sensitivity, robustness and operation and by providing commercial fabrication services, or licensing others to do so. In other commercial activity we have discussed possible routes forward with leading cryogenic equipment manufacturers Oxford Instruments and Blufors. We continue to expand our engagement with industry both as developers of the technology and as end-users.

Longer term, specific examples of technology and sensor impact include pushing the boundaries of hybrid systems such as the HyQUID; closing the quantum electrical triangle through a realisation of the Ampere using Coherent Quantum Phase Slip (CQPS) devices; scanning probe charge detection with high resolution based on CQPS; superconducting amplifiers beyond the quantum limit; quantum coherent conversion of optical to microwave photon for quantum encrypted networks; on-demand microwave photon sources and sources of entangled microwave photons based on superconducting qubits, and more.

Beneficiaries are thus: manufacturers of devices of novel functionality based on new materials or new concepts; the scientific instruments industry, including cryogenic and superconducting technologies industries; SMEs in emerging technology areas and National Measurement Institutes. We will be aided by the new Department of Electronic Engineering at RH in developing a streamlined route from physics through to engineering and exploitation. Longer term impact is envisaged through applications of nano-devices based on exotic quantum materials, quantum meta-materials, high kinetic inductance materials and materials for quantum phase slip, exploiting our expertise across nanoscale fabrication and superconducting materials development, leading to new products.

People: A key impact is through the rigorous training of highly skilled manpower, demonstrated by our track record. This requires the best equipment, the subject of this proposal, coupled to our high level of expertise, experience and innovative approaches. Many of our graduate and PDRA alumni are employed by the leading superconducting quantum circuit laboratories and companies.