Topological mesoscopic superfluidity of 3He

Lead Research Organisation: Royal Holloway, University of London
Department Name: Physics

Abstract

Helium remains liquid down to the absolute zero of temperature through a combination of relatively weak interatomic interactions and quantum zero point motion. It provides models for studying systems of strongly interacting bosons (4He) and fermions (3He). These materials have played a key role in the development of concepts central to condensed matter physics: Bose-Einstein condensation; macroscopic quantum physics; topological phase transitions; the Landau Fermi liquid theory of electrons in metals; unconventional superconductivity; topological quantum matter. The richest system is superfluid 3He (recognized in the 1996 and 2003 Nobel Prizes), the conceptual reach of which is described by Volovik in terms of a "3He-centric universe", conceptually linked to most major fields of physics.

Condensed matter systems feature in every modern technology. The development of this technology has relied on the discovery and creation of new materials with new phases and often unanticipated properties, as well as hybrid devices which combine these materials, increasingly on the nanoscale.

Recently the understanding of new phases solely in terms of symmetry breaking has been shown to be inadequate in some cases. This is the notion of topological quantum matter (2016 Nobel Prize). Two important classes of quantum matter are at the centre of attention: topological insulators and topological superconductors. Usual insulators do not conduct electricity, because of an energy gap between filled and empty energy bands. But in a topological insulator the momentum space topology of the band structure necessarily gives rise to conducting surface excitations. On the other hand, as a metal is cooled into its superconducting state, a gap emerges. Topological superconductors also support surface/edge excitations, and there are substantial efforts to identify materials that are bulk topological superconductors.

This project will exploit superfluid 3He, known to support two distinct topological superfluid phases in bulk, establishing the new research direction of topological mesoscopic superfluidity. Under nanoscale confinement, this material provides a unique model for topological superconductivity. The subtle interplay between symmetry and topology in these materials is an open question. Our approach will be to confine 3He in precisely engineered geometries to create hybrid nanostructures, allowing a degree of control that is unprecedented. Confinement and periodic structures, with liquid pressure as a tuning parameter of Cooper pair diameter, will induce new superfluid phases, for which the order parameter symmetry will be inferred from nuclear magnetic resonance. These materials will be building blocks for hybrid mesoscopic superfluid systems.

Excitations emerge at surfaces/edges/interfaces of the topological superfluid. As well as the interface with inert matter, where we can tune surface scattering in situ, stepped confinement in hybrid structures will create intra-fluid interfaces of the highest quality. Surface and edge spin currents in time reversal invariant superfluid 3He-B will be investigated by NMR and their coupling to confined Anderson-Higgs order parameter collective modes, as well as nano-wires of diameter similar to that of Cooper pairs. Our ambition is to detect non-local response of the surface Majorana modes. Edge states in chiral superfluid 3He-A will be investigated by a predicted anomalous Hall effect in mass and thermal transport. Interface states will be investigated by thermal transport.

This project has a strong international collaborative dimension, including partnerships with Cornell, NIST and PTB (Berlin). Partnerships with theorists from the USA, Europe and Japan are central to the design and interpretation of experiments. Partnerships within the scientific instruments industry will deliver short-medium term impact from the technical developments central to this project.

Planned Impact

Who will benefit?
Topologically protected quantum computing is an ambitious but important long term challenge in quantum technology. The fundamental understanding of topological superconductivity is key to establishing the feasibility of routes to topologically protected quantum computing using such materials. With materials science advances in unconventional superconductivity we can also anticipate future devices based on thin films of these materials with potentially new functionality.

Our fundamental research drives forward the development of state-of-the-art research capacity. These developments in instrumentation measurement systems directly benefit the scientific instruments industry in the short-medium term, especially those focussed on cryogenics, nanoscience and superconducting technologies, widening its customer base. This is fostered by the global reach of UK industry in this sector. In addition new experimental methods, for example the measurement of temperature and new NMR methods, impact on society through National Measurement Institutes.

Collaboration between the UK, mainland Europe and leading groups in the USA, both theoretical and experimental, as well as strong links with Asia increases the opportunity for international impact. We contribute to the scientific society through work for international funding agencies, scientific academies, and globally via IUPAP.

The general public, including young people tend to be excited and motivated by laboratory-based fundamental science at one of Nature's frontiers, and the technical challenges we meet.

How will they benefit?
Advances in the fundamental understanding of topological superconductivity will be underpinned by the research on topological mesoscopic superfluid 3He as a model system. The propagation of these ideas by theorists across discipline boundaries through networking, workshops, will play a key role. The topological classification of condensed matter is a universal scheme, so advances in understanding on model systems will enter the canon of the subject, and are essential for long-term technological progress.

In the short term we expect to continue to export highly trained manpower to industry. This research, at the frontier of the subject, combines new techniques in ultralow temperature physics new measurement techniques, advances in nanofluidics, and crucially a robust confrontation between theory and experiment. Individuals trained in these skills and expertise, equipped with rigorous scientific methodology, are an important resource enhancing economic competitiveness.

Instrumentation development plays a central role in the proposed research. We will work towards short-term impact in: cryogen-free nuclear demagnetization platforms; advances in noise thermometry; definition of the Kelvin; improved heat exchangers; applications of novel superconducting devices to NMR (with potential future applications in medicine).

What will be done to ensure that they benefit?
This proposal includes a number of Project Partnerships. Collaborations are well established with the scientific instruments industry (Oxford Instruments Nanoscience), and here we establish a new partnership with York Instruments.

We have long-term partnerships with National Measurement Institutes, including: strategic partnership with NPL; Project Partnership with PTB. Membership of European Microkelvin Platform with arrangements for technology exchange, innovation management and public engagement both supports our impact agenda, and helps us target areas where we can make a unique contribution. Nationally, impact on Quantum Technology will be enhanced by the new UK Centre of Excellence for superconducting and hybrid quantum systems at Royal Holloway.

Finally, we will develop our public engagement strategy, supported by our dedicated Physics Outreach Officer, through talks, videos, posters, news stories, and enhanced on-line presence.

Publications

10 25 50
 
Description In hybrid mesoscopic devices made from topological superfluid 3He, confinement is the key control parameter which determines the superfluid order parameter. In experiments on 3He confined in a 200 nm cavity we have demonstrated that it is possible to tune the surface scattering from diffuse to specular, by coating the surface with a superfluid 4He film. We show, with our theory collaborators, that both the suppression of Tc and of the superfluid gap as a function of surface specularity can be accounted for using quasiclassical theory. We discovered that with a surface boundary layer of localised magnetic 3He, stronger Tc suppression is observed. Our theory collaborator (Vorontsov) has recently developed a new model for the impact of surface spin-slip scattering on superfluidity to account for our results. This has wide implications in topological superconductivity and its applications, including the feasibility of topological quantum computing. This work has been published in Nature Communications. We have built a system to extend this work by implementing a broadband NMR technique; the intention is to probe the influence of the 3He surface boundary layer on the superfluid order parameter directly, by measurements of the frequency shift.

The experimentally demonstrated elimination of Tc suppression for specular walls opened the door to the study of superfluid 3He in much thinner cavities, entering the quasi-two-dimensional limit. However we encountered a number of problems with silicon surfaces in the first generation of such cells. These now appear to have been resolved; we used a spectrum of surface probe techniques through collaborators at NPL. Better control over silicon surface passivation is now yielding good results.

Experiments have been performed on a cavity of height 80 nm, close to the coherence length at zero pressure. Complete suppression of superfluidity at this pressure arises under diffuse surface scattering conditions. Our SQUID NMR experiment demonstrates that we can create close to specular scattering conditions, eliminating both Tc and gap suppression, and stabilize the superfluid A phase. The implication is that quasi-two-dimensional films of chiral superfluid, of thickness much smaller than the coherence length, can be studied. Here a multiplicity of new phenomena are predicted. The results are the subject of a paper in preparation for Phys.Rev.Lett.

Analysis of NMR experiments on superfluid 3He confined in a 1.1 micron high cavity has provided evidence for a spatially modulated superfluid phase. Uniquely in superfluid 3He, NMR can clearly fingerprint the order parameter. Such phases, in which spatially modulation of superfluid order arises spontaneously, are sought in a wide range of systems: layered organic superconductors; heavy fermion superconductors; cuprate superconductors, ultracold fermionic gases; astrophysical objects. In our case, while a one-dimensional stripe modulation was predicted by Vorontsov and Sauls, we identify a two dimensional modulation, which we refer to as "polka-dot". This work was published in February 2019 in Physical Review Letters. It was selected as an "Editors' Suggestion" and featured in an article in "Physics". Recent, as yet unpublished, theoretical work shows that both 1D and 2D spatially modulated ("pair density wave") phases are topologically stable. This is an exciting result, with significant consequences.

This work was followed up, using different techniques, by a group at Alberta (and their work was published in Phys. Rev. Lett). We believe that the conclusions drawn by these authors are incorrect, and we published a Comment in Phys. Rev. Lett to this effect.

In collaboration with Cornell we made the first study of thermal transport in 3He in strongly confining channels (measurements made at Cornell). This work was published in Nature Communications. We are also collaborating on a study of the superfluid AB transition in a special nanofluidic cell for operation up to high pressures (cell installed at Royal Holloway).

A key strand of this research is the study of superfluid 3He in hybrid structures incorporating regions of different cavity height to both stabilize different phases and create interfaces. These will be investigated using new thermal transport techniques. This activity was strongly impacted by the covid-19 pandemic. Nanofabrication facilities at both University of Southampton and Cornell University failed to deliver satisfactory results; satisfactory bonding of wafers was the main, but not the only, roadblock. This situation was resolved by use of facilities at the University of Michigan, which allowed our PhD student access as a user, and where all required processes were available. Two successful fabrication runs were executed. This contributes to increased capability in delivering state-of-the-art nanofluidic structures.

During this time a significant upgrade of the cryostat was implemented, including the installation of broadband NMR capability. Superconducting microcoils for local NMR have been fabricated at with PTB (Braunschweig). Preliminary work has been done of nanofluidic cells for acoustic measurements (these do not require bonding) using the Superfab facility. Superconducting HyQUIDs have been fabricated at SuperFab (Royal Holloway) as a potential replacement for SQUIDs in signal read-out for noise thermometry and NMR.
Exploitation Route These findings are of broad relevance as follows:
The result on surface scattering in topological superfluid 3He (with establish unconventional p-wave pairing) is relevant to future mesoscopic device applications of topological superconductors, of relevance to future quantum technology.
The experimental discovery of spatially modulated superfluidity/superconductivity is of wide interest and relevance, as mentioned in "key findings".
Sectors Manufacturing, including Industrial Biotechology

 
Description Summary: Although the primary purpose of this project is fundamental research on topological superfluidity it has critically underpinned major achievements in low temperature refrigeration and thermometry. These include the delivery of a fully engineered high performance cryogen-free microkelvin platform, which significantly promotes the accessibility of this temperature regime to a potentially wide user base in quantum technology and quantum materials. Our research has also underpinned the new definition of the kelvin as part of the International System of Units (SI) in 2019; current sensing noise thermometry pioneered and developed by us was also included in the Mise en Pratique for the range 1 mK to 1K. Superfluid 3He is a model system for topological quantum matter, and a benchmark for topological superconductivity. Although no topological superconductor has been definitively identified, the anticipated intellectual impact is high with significant future impact if topologically protected quantum computing (TPQC) is enabled. Our work has already demonstrated the fragility of potential majorana surface states, the manipulation of which underpins TPQC, and future work on superfluid 3He may well conclusively identify these exotic and useful excitations and understand their properties for the first time. A significant and wide impact in the shorter term derives from the recognised importance of research on matter under extreme conditions, in particular low temperatures. Developing capability in this sector by enhancing measurement technique, metrology and instrumentation, is a key feature of this research, and we have contributed in several ways. This impact has been achieved through close collaboration with the industrial sector (primarily Oxford Instruments Nanoscience) and National Measurement Institutes. We have constructed and tested a fully-engineered high-performance cryogen-free microkelvin platform. A mode of operation has been established in which it is possible to be below 1 mK for 95% of the time. Planned commercialisation, through technology transfer, will promote the accessibility of this temperature regime to a wide user-base. We operate as an access laboratory in European Microkelvin Platform (EMP) www.emplatform.eu, a European Advanced Infrastructure, funded by European Commission. Our work with users has demonstrated the importance of the microkelvin regime to advance research on quantum materials and quantum technology. We have achieved success in cooling a variety of systems, sensors and devices, including advances of strategic significance in superconducting quantum technology. Furthermore the new platforms exploiting these new technologies will underpin anticipated growth in fundamental physics research of high discovery potential and scope for future impact. An example of a project running already is the QUEST-DMC consortium funded by UKRI's QTFP programme and led by Royal Holloway (PI Andrew Casey). As a historical note: we made the first proof-of-principle demonstration of cryogen free nuclear demagnetization, which was the subject of an Impact Case Study to REF2014, and highlighted in the Institute of Physics 2015 publication "Inspirational physics for a modern economy", as well at a special session at the APS March meeting in 2015. The development of the current prototype system was included in 2019 as a deliverable of EMP, which is now fully achieved. In partnership with national measurement institutes in the programmes "Implementing the new kelvin 1 and 2" (2012-2019), the current sensing noise thermometer was selected as one of the ultra-low temperature primary thermometers required to prepare for the 2019 redefinition of the kelvin. The International System of Units, directed from the International Bureau of Weights and Measures in Paris (BIPM), constitutes a coherent set of units by which any measurable quantity of interest in research, industry, trade or society can be quantified. The signatory states of the Metre Convention represent about 98% of the world's economy, so the SI is the basis of international trade and supports the global measurement quality infrastructure through national metrology institutes (such as the National Physical Laboratory in the UK). The new kelvin scale was launched on the 20th May 2019 and represents the most significant change since the SI was formally agreed in 1960. The new definition of the kelvin also requires reliable, traceable methods to enable dissemination of the scale to international research organisations and industry. It is the role of the International Committee for Weights and Measures (the CIPM) and the Consultative Committee for Thermometry (CCT) to facilitate this through the publication of a detailed set of instructions that describe how you can locally realise the new temperature scale, called the Mise en Pratique (the practical application), specifically for the kelvin the MeP-K-19. The current sensing noise thermometer developed by the Royal Holloway group was selected as one of the three thermometers to be admitted into the Mep-K for the lowest temperature range of the scale (1 mK to 1 K), after it was demonstrated that it met the stringent conditions for reliable, low uncertainty, thermodynamic temperature values in direct comparison to the pre-existing provisional low temperature scale, PLTS-2000. This work is of significant benefit to the cryogenic industry. Companies within the UK and the rest of Europe represent the world's largest suppliers of cryogenic equipment, dilution refrigerators and cryogen free ultra-low temperature systems (Oxford Instruments (UK), Cryogenic Ltd (UK), Leiden Cryogenics (The Netherlands), Bluefors (Finland), Entropy Cryogenics (France). The practical primary low temperature thermometers have been trialled in an industrial setting at Oxford Instruments, demonstrating the feasibility of reliable dissemination of thermodynamic temperature (i.e. directly linked to the new kelvin definition) at these very low temperatures. Oxford Instruments is a global company that creates high performance cryogenic and cryogen-free environments for ultra-low temperature and high magnetic field applications in physics, chemistry and materials science. They recognised the value of this work through sponsoring two PhD students. We have filed a patent for a fast, practical ultra-low temperature current sensing noise thermometer. The power of these methods has been demonstrated by heat capacity studies over the wide temperature range 200 µK to 90 mK. This technical capability creates an opportunity to disseminate the new kelvin through a licencing agreement with a commercial supplier. This should help maintain the competitiveness, at a time when there is a relative explosion in the usage of cryogen-free dilution refrigerators driven by the quantum revolution. We have also pioneered a new method to measure the thermal boundary resistance between low area metallic foils and helium, having limited residual heat leaks to sub-10fW. This can potentially lead to new heat exchangers and Oxford Instruments is supporting this work by a PhD studentship. This research has driven us to establish new capabilities in the design and construction of nanofluidic cells. It is required to bring together a number of nanofabrication processes, for several of which an effective UK capability does not seem to exist. These include wafer bonding techniques, which are of generic significance in quantum technology and important in 3D architectures. This has now been addressed by acquisition of a new instrument for SuperFab, funded by EPSRC. Impact through outreach/public engagement has been delivered through evening lectures. John Saunders was Chair of IUPAP (International Union of Pure and Applied Physics) Commission C5, and a Vice-President on the IUPAP Executive Council. His term of office ended in 2017. He is a member of the executive board of the European Microkelvin Platform. Since 2020 he is director of the Advanced Quantum Science and Technology Catalyst at Royal Holloway.
First Year Of Impact 2019
Sector Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Education,Electronics,Environment,Healthcare,Manufacturing, including Industrial Biotechology
Impact Types Economic

 
Description Underpinning the 2019 redefinition of the kelvin, as part of the Mise en Pratique.
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
Impact In 2019 the SI unit of temperature, the kelvin, was redefined as part of the most significant overhaul of the seven SI units since their adoption. Our research provides techniques to disseminate the new scale in the ultralow temperature regime, critical for future quantum-enhanced technologies driving the second quantum revolution.
URL https://www.bipm.org/en/publications/mises-en-pratique/
 
Description Equipment for Quantum Science and Technology
Amount £465,575 (GBP)
Funding ID EP/V036297/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 09/2020 
End 04/2022
 
Description INFRAIA-01-2018-2019 European Microkelvin Platform
Amount € 9,941,066 (EUR)
Funding ID 824109 
Organisation European Commission 
Sector Public
Country European Union (EU)
Start 01/2019 
End 12/2022
 
Title Accompanying data for "Fragility of surface states in topological superfluid 3He" 
Description This dataset includes the measured and calculated values of the suppressed superfluid transition temperature and the suppressed energy gap of superfluid helium-3 confined in a 192 nm high slab-shaped cavity with different quasiparticle scattering boundary conditions.The article detailing the findings of this study, and the used methods and techniques, has been published in Nature Communications 12, 1574 (2021). https://doi.org/10.1038/s41467-021-21831-yData from the experiments:'expr_Tc_suppression_[boundary condition].dat' files list the measured values of superfluid transition temperature both in the confined cavity and in the bulk markers corresponding to different boundary conditions and various pressures, i.e. various values of effective cavity height. These values are included in Figures 2a,b and 3a in the manuscript.'expr_gap_[boundary condition]_[pressure].dat' files give the measured temperature dependence of the spatially averaged energy gap of superfluid A phase of helium-3 corresponding to two boundary conditions and various pressures. Values of the gap are based on the measured NMR frequency shift in the superfluid state as described in Supplementary Note 1 in the manuscript. Two pressures are included in Figure 2c in the article. All four pressures in specular case are shown in Supplementary Figure 8 and all four pressures in diffuse case in Supplementary Figure 9.'initial_slopes_[boundary condition].dat' give the measured initial slopes of the superfluid frequency shift versus temperature determined within 10% range below the measured superfluid transition temperature in the cavity for two boundary conditions and various pressures. These values are needed in conversion between the frequency shift and the energy gap and are plotted in Supplementary Figure 4 in the manuscript.Calculations:'calc_Tc_suppression_S[specularity].dat' show the calculated suppressed superfluid transition temperature as a function of effective cavity height for various different specularities.'calc_gap_S[specularity]_D[effective height].dat' give the calculated spatially averaged values of the energy gap of superfluid 3He-A as a function of temperature, corresponding to different surface specularities and effective heights of the cavity. The effective heights for specularity S = 0.10 correspond to mean heights of the cavity at four pressures used in the experiments, determined by the limits set by the uncertainty in the height measurement and by the small pressurre-dependent height distortion. The diffuse S = 0.00 calculations exactly match these values or are off by insignificant amount.In all the calculations we have used the quasiclassical weak-coupling approach, as described in the Supplementary Note 3 of the manuscript. In gap calculations also the trivial pressure-dependent strong-coupling scaling has been included, as detailed in Supplementary Note 4.Values of bulk (or fully specular) superfluid transition temperature are given by D. S. Greywall in Phys. Rev. B 33, 7520 (1986) (https://doi.org/10.1103/PhysRevB.33.7520). These values are used to convert the unitless gap calculations into real units.Values of the weak-coupling bulk energy gap of 3He-A can be found, for example, by using E. V. Thuneberg's calculator from http://ltl.tkk.fi/research/theory/qc/bcsgap.html. The values as a function of temperature are also given in file 'calc_gap_bulk.dat'. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://royalholloway.figshare.com/articles/dataset/Accompanying_data_for_Fragility_of_surface_state...
 
Title Accompanying data for "Fragility of surface states in topological superfluid 3He" 
Description This dataset includes the measured and calculated values of the suppressed superfluid transition temperature and the suppressed energy gap of superfluid helium-3 confined in a 192 nm high slab-shaped cavity with different quasiparticle scattering boundary conditions.The article detailing the findings of this study, and the used methods and techniques, has been published in Nature Communications 12, 1574 (2021). https://doi.org/10.1038/s41467-021-21831-yData from the experiments:'expr_Tc_suppression_[boundary condition].dat' files list the measured values of superfluid transition temperature both in the confined cavity and in the bulk markers corresponding to different boundary conditions and various pressures, i.e. various values of effective cavity height. These values are included in Figures 2a,b and 3a in the manuscript.'expr_gap_[boundary condition]_[pressure].dat' files give the measured temperature dependence of the spatially averaged energy gap of superfluid A phase of helium-3 corresponding to two boundary conditions and various pressures. Values of the gap are based on the measured NMR frequency shift in the superfluid state as described in Supplementary Note 1 in the manuscript. Two pressures are included in Figure 2c in the article. All four pressures in specular case are shown in Supplementary Figure 8 and all four pressures in diffuse case in Supplementary Figure 9.'initial_slopes_[boundary condition].dat' give the measured initial slopes of the superfluid frequency shift versus temperature determined within 10% range below the measured superfluid transition temperature in the cavity for two boundary conditions and various pressures. These values are needed in conversion between the frequency shift and the energy gap and are plotted in Supplementary Figure 4 in the manuscript.Calculations:'calc_Tc_suppression_S[specularity].dat' show the calculated suppressed superfluid transition temperature as a function of effective cavity height for various different specularities.'calc_gap_S[specularity]_D[effective height].dat' give the calculated spatially averaged values of the energy gap of superfluid 3He-A as a function of temperature, corresponding to different surface specularities and effective heights of the cavity. The effective heights for specularity S = 0.10 correspond to mean heights of the cavity at four pressures used in the experiments, determined by the limits set by the uncertainty in the height measurement and by the small pressurre-dependent height distortion. The diffuse S = 0.00 calculations exactly match these values or are off by insignificant amount.In all the calculations we have used the quasiclassical weak-coupling approach, as described in the Supplementary Note 3 of the manuscript. In gap calculations also the trivial pressure-dependent strong-coupling scaling has been included, as detailed in Supplementary Note 4.Values of bulk (or fully specular) superfluid transition temperature are given by D. S. Greywall in Phys. Rev. B 33, 7520 (1986) (https://doi.org/10.1103/PhysRevB.33.7520). These values are used to convert the unitless gap calculations into real units.Values of the weak-coupling bulk energy gap of 3He-A can be found, for example, by using E. V. Thuneberg's calculator from http://ltl.tkk.fi/research/theory/qc/bcsgap.html. The values as a function of temperature are also given in file 'calc_gap_bulk.dat'. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://royalholloway.figshare.com/articles/dataset/Accompanying_data_for_Fragility_of_surface_state...
 
Description Cornell University 
Organisation Cornell University
Country United States 
Sector Academic/University 
PI Contribution Collaborative research on superfluid helium-3.
Collaborator Contribution Fabrication of nanofluidic sample chambers.
Impact Joint publications.
 
Description Kyoto University 
Organisation University of Kyoto
Department Department of Physics
Country Japan 
Sector Academic/University 
PI Contribution Access to experimental data
Collaborator Contribution Theoretical support and discussions
Impact Input into papers and talks
Start Year 2018
 
Description Montana State University 
Organisation Montana State University
Department Department of Physics
Country United States 
Sector Academic/University 
PI Contribution Access to experimental data
Collaborator Contribution Theoretical input into project
Impact Input into research talks / papers.
Start Year 2017
 
Description Northwestern_Theory 
Organisation Northwestern University
Country United States 
Sector Academic/University 
PI Contribution Experimental research and discussions on theory. Travel support.
Collaborator Contribution Theoretical collaboration. Facilitating engagement with a wider community of theorists.
Impact Collaboration is ongoing.
Start Year 2011
 
Description Oxford Instruments Nanoscience 
Organisation Oxford Instruments
Country United Kingdom 
Sector Private 
PI Contribution RHUL Low temperature laboratory group have collaborated with OIN on designs of cryogenic platforms. Our cryostat ND2 was the first example of what has become the Kelvinox 400 HA, where the design was influenced by our requirements for nuclear demagnetisation. RHUL/OIN jointly built a prototype of a combined nuclear demagnetisation cryogen free cryostat, the RHUL team demonstrated sub mK performance of a cryogen-free cryostat for the first time. OIN are world leaders in manufacturer of cryostats and we are working with them to replace nuclear orientation thermometers with our current sensing noise thermometer. Through a Memorandum of Understanding the RHUL provide consultation services for the design engineers at OI.
Collaborator Contribution Consultation on specialist magnet designs, Provision of engineered components, Discounts on new cryogenic platforms OIN provided £20,000 of sponsorship for ULT 2008: Frontiers of Low Temperature Physics
Impact RHUL: REF 2014 Impact Case Study London Low Temperature Laboratory http://dx.doi.org/10.1088/1367-2630/15/11/113034 http://dx.doi.org/10.1007/s10909-014-1147-z
 
Description Oxford University 
Organisation University of Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution Access to experimental data
Collaborator Contribution Theoretical support and discussions
Impact Input into papers and talks
Start Year 2018
 
Description PTB_SQUIDs 
Organisation Physikalisch-Technische Bundesanstalt
Country Germany 
Sector Academic/University 
PI Contribution Development of application of SQUIDs in high precision instrumentation.
Collaborator Contribution Design and fabrication of SQUIDs.
Impact Joint publications. New instrumentation for NMR and noise thermometry.
 
Description University of Jyväskylä 
Organisation University of Jyvaskyla
Department Department of Physics
Country Finland 
Sector Academic/University 
PI Contribution Access to experimental data
Collaborator Contribution Theoretical support
Impact Input into talks an papers
Start Year 2018
 
Title CURRENT SENSING NOISE THERMOMETER 
Description A current sensing noise thermometer comprising: a sensor resistor thermally coupled to a target to be measured; a superconducting coil; superconducting thermal breaks between respective ends of the sensor resistor and respective ends of the superconducting coil; and a superconducting flux sensor; wherein the sensor resistor, superconducting coil and superconducting thermal breaks form a loop inductively coupled to the superconducting flux sensor. There may be a noise filter between the sensor resistor and the superconducting coil. 
IP Reference WO2021239513 
Protection Patent application published
Year Protection Granted 2021
Licensed No
Impact Current sensing noise thermometer is now part of the mise en pratique for the Kelvin. This patent is for a fast robust thermometer that is linked to this definition.
 
Title High performance cryogen free microkelvin platform 
Description High performance cryogen free microkelvin platform will promote access to this temperature regime for a wide user base. Focus is on research on quantum materials and quantum technology. 
Type Of Technology New/Improved Technique/Technology 
Year Produced 2020 
Impact See Impact narrative. 
 
Description Astrophysics schools residential course 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact 60 A-level students attended a Astrophysics residential course at RHUL organised by the SmallPiece trust, Dr, Andrew Casey gave a lecture at this course on low temperature properties of space, cryogenics and the relationship with the superfluid research at RHUL
Year(s) Of Engagement Activity 2018,2019
 
Description Girls into Physics Residential Course 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact In collaboration with the Smallpiece Trust, we ran a three-day residential course aimed at addressing the underrepresentation of women in physics by providing a mixture of physics activities for year 10/12 female school children from a range of schools. As part of this activity, Dr. Andrew Casey provided a lecture and demonstration about some of the exciting discoveries in low temperature physics. In 2020 this event was delivered online.
Year(s) Of Engagement Activity 2017,2018,2019,2020
URL https://www.royalholloway.ac.uk/physics/events/eventsarchive/girls-into-physics-residential.aspx
 
Description Institute of Physics Low Temperature Techniques Course 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact The purpose of the meeting is to disseminate best practice and raise awareness of new innovations in low temperature techniques and thermometry to each new national cohort of PhD students and postdoctoral researchers embarking on a research career at low temperatures. In addition we raise the awareness of how those skills can be employed in an industrial environment. Each year the event is attended by around 50 delegates (mainly 1st year PhD students, occasionally international), the students report a raised awareness and begin to create the support network with each other and the speakers at the event that will help them during there career. The event is organised and chaired by: Dr. Andrew Casey (with support from the IOP) Dr. Andrew Casey and Dr. Jan Nyeki both give presentations at the event. The event is supported by an annual grant from the IOP Low Temperature group of £1000, which is used to reduce the cost of attendance. The event is publicised by the IOP through it's website and newsletters. An e-version of the material presented is distributed to all of the delegates.
grant from the IOP Low Temperature group of £1000, which is used to reduce the cost of attendance. The event is publicised by the IOP through it's website and newsletters. An e-version of the material presented is distributed to all of the delegates.
Year(s) Of Engagement Activity 2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021
URL https://www.iopconferences.org/
 
Description Institute of Physics Low Temperature Techniques Course 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact The purpose of the meeting is to disseminate best practice and raise awareness of new innovations in low-temperature techniques and thermometry to each new national cohort of PhD students and postdoctoral researchers embarking on a research career at low temperatures. In addition, we raise the awareness of how those skills can be employed in an industrial environment. Each year the event is attended by around 50 delegates (mainly 1st year PhD students, occasionally international), the students report a raised awareness and begin to create a support network with each other and the speakers at the event that will help them during their career.
The event is organised and chaired by: Dr. Andrew Casey (with support from the IOP)
Dr. Andrew Casey and Dr. Jan Nyeki both give presentations at the event.
The event is supported by an annual grant from the IOP Low Temperature group of £1000, which is used to reduce the cost of attendance.
The event is publicised by the IOP through it's website and newsletters.
An e-version of the material presented is distributed to all of the delegates.
The 2020 event was online only.
Year(s) Of Engagement Activity 2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021
URL https://www.iopconferences.org/iop/frontend/reg/thome.csp?pageID=407153&eventID=818&eventID=818&CSPC...
 
Description Quantum Technology Showcase (London) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Highlighting the quantum technology capabilities to a wide audience. Following this meeting, a delegation from the US embassy in London requested an onsite visit to discuss future collaborations.
Year(s) Of Engagement Activity 2021
URL https://ktn-uk.org/events/uk-national-quantum-technologies-showcase-2021/
 
Description Royal Holloway, Physics Taster Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Royal Holloway Physics Taster Days are one day events held in the Physics department at Royal Holloway where we invite A-level physics students from schools within our region to experience university level physics. Typically each event is attended by between 50-100 students. In some years the event has been targeted at widening participation by inviting schools that do not have a strong track record in physics provision. Dr. Andrew Casey has given a lecture every year at these events.
Surveys of the students before and after the event suggest that students are more to choose physics at degree level after attending the event. In 2020 the event was online.
Year(s) Of Engagement Activity 2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020
URL https://www.royalholloway.ac.uk/physics/outreach/a-level/tasteofphysics.aspx
 
Description Royal Holloway, Science Festival 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Our annual science festival is designed to inspire and inform the general public about the research at Royal Holloway. Each year the event is attended by around 5000 members of the general public. Dr. Andrew Casey and Dr. Jan Nyeki provide lectures and demonstrations throughout the event each year. Dr. Andrew Casey runs the low temperature zone, comparing the low temperatures achieved in the Universe with those that can be achieved in the laboratory, and highlights the physics that can be performed at these low temperatures.
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019
URL https://www.royalholloway.ac.uk/science/sciencefestival/home.aspx
 
Description Scout Visit (London) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other audiences
Results and Impact 30 explorer scouts plus scout leaders attended a visit to our research organization for a talk on low-temperature physics. Several scouts reported plans to change their A0level choice to include physics.
Year(s) Of Engagement Activity 2021
 
Description Super Cool Baking (Richmond and Hillcroft Adult Community College) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact A pilot scheme to reach the low science capital adult audience with funding from the regional IOP branch. (London and South East). The premise was to combine physics discussions and demonstrations with an adult cookery class. Cooking is one of the top pastimes amongst adults and provided a vehicle to connect with an audience that would not have come to a science lecture. The feedback from the evening was good and further funding is being sought to widen the pilot scheme to other venues.
Year(s) Of Engagement Activity 2019
URL https://www.eventbrite.co.uk/e/super-cool-baking-an-evening-of-discovery-tickets-68843088531#
 
Description Widening Participation Event 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact 80 students from West London schools attended a University taster day organized by the physics outreach officer. Dr. Casey provided a lecture with demonstrations about the exciting possibilities of low temperature research. Students, who previously had not considered University as a future option reported that they were now motivated to pursue this.
Year(s) Of Engagement Activity 2020