Optical sensing of electronic interactions in two-dimensional semiconductors using a novel cryogenic surface force apparatus

The project will harness the state-of-the-art expertise in instrument design and engineering of Razorbill Instruments, based in Edinburgh, and the expertise in two-dimensional materials and optical spectroscopy at the Quantum Photonics Lab (QPL) at Heriot-Watt University, led by Prof. Brian Gerardot.

The first part of the project will be to deliver the main design requirements: (i) Designing an optically transparent probe that can gently contact a surface; (ii) Designing a mechanism to allow in-plane motions with ~angstrom precision, and (iii) Designing an optical sensing feedback method for these mechanisms so that the motions are controlled and measured. The industrial partner, Razorbill Instruments, are experts in precision motion at cryogenic temperature and will be able to advise on optimum designs.

Once the instrument design/build/test cycle is complete, the student will join the team in the QPL to take part in the ground-breaking experiments that exploit this novel instrument. A particularly exciting goal is to optically probe 2D semiconductor heterostructures known as moiré materials as they are tuned in-situ by the instrument. Moiré materials, formed by a slight difference in periodicity or twist angle between two crystals, give rise to a wealth of intriguing collective phenomena (such as superconductivity, quantum spin liquids, and exotic types of magnetism) that cannot easily be investigated in conventional materials. The student will work closely with PhD students and post-docs in the QPL to fabricate the atomically thin crystals and perform the optical spectroscopy at cryogenic temperatures.

Complementing our Pathways to Impact document, here we state the expected real-world impact, which is of course the leading priority for our industrial partners. Their confidence that the proposed CDT will deliver valuable scientific, engineering and commercial impact is emphasized by their overwhelming financial support (£4.38M from industry in the form of cash contributions, and further in-kind support of £5.56M).

Here we summarize what will be the impacts expected from the proposed CDT.

(1) Impact on People
(a) Students
The CDT will have its major impact on the students themselves, by providing them with new understanding, skills and abilities (technical, business, professional), and by enhancing their employability.
(b) The UK public
The engagement planned in the CDT will educate and inform the general public about the high quality science and engineering being pursued by researchers in the CDT, and will also contribute to raising the profile of this mode of doctoral training -- particularly important since the public have limited awareness of the mechanisms through which research scientists are trained.

(2) Impact on Knowledge
New scientific knowledge and engineering know-how will be generated by the CDT. Theses, conference / journal papers and patents will be published to disseminate this knowledge.

(3) Impact on UK industry and economy
UK companies will gain a competitive advantage by using know-how and new techniques generated by CDT researchers.
Companies will also gain from improved recruitment and retention of high quality staff.
Longer term economic impacts will be felt as increased turnover and profitability for companies, and perhaps other impacts such as the generation / segmentation of new markets, and companies receiving inward investment for new products.

(4) Impact on Society
Photonic imaging, sensing and related devices and analytical techniques underpin many of products and services that UK industry markets either to consumers or to other businesses. Reskilling of the workforce with an emphasis on promoting technical leadership is central to EPSRC's Productive Nation prosperity outcome, and our CDT will achieve exactly this through its development of future industrially engaged scientists, engineers and innovators. The impact that these individuals will have on society will be manifested through their contribution to the creation of new products and services that improve the quality of life in sectors like transport, dependable energy networks, security and communications.

Greater internationalisation of the cohort of CDT researchers is expected from some of the CDT activities (e.g. international summer schools), with the potential impact of greater collaboration in the future between the next generations of UK and international researchers.