A practical quantum simulator: simulating molecular vibrations with photons

Lead Research Organisation: University of Bristol
Department Name: Physics

Abstract

Computer simulations of physical models have become a vital tool in science and engineering. For example, the aerodynamics and chassis integrity for a new car design will be fully simulated on a computerised model, long before production begins, while biologists will use a simplified computer model to simulate the dynamics involved in protein folding. In both of these cases, the physics underlying the model to be simulated is that of the familiar, classical world, as is the information that is processed. In contrast, chemists working with systems at the microscopic scale (quantum chemists) must incorporate quantum physics into their physical models. But these models come up against the intractability of simulating even modestly sized quantum systems on classical computers.

The number of possible configurations of any system grows exponentially with its degrees of freedom, just like the number of heads/tails configurations of a row of coins doubles with each additional coin. Since a quantum system can exist simultaneously across all of its configurations, its evolution is too large to be simulated with a classical computer. Therefore, quantum mechanical models for classical computers are necessarily limited while more compete models are fundamentally intractable to classical simulation. Yet increasingly, scientists need to understand the role of quantum physics, for example in biological molecules.

The famous physicist and Nobel Laureate, Richard Feynman, identified this problem in a seminal lecture in 1982. He also proposed a solution. Feynman suggested using one controllable quantum system to simulate the model for the quantum system one wishes to study. The ultimate realisation of this ingenious concept is a digital quantum simulator that theoretically can be programmed to simulate any quantum system. Building this device is the focus of an increasingly intensive international effort, or competition. This effort is likely to be long term since isolating, digitising, and coherently controlling large quantum systems has proved to be highly challenging, due to their inclination to couple to the environment, decohere, and behave classically. After all, the world we see around us is classical, not quantum. Therefore, the road to a quantum simulator that surpasses the capabilities of classical computers seems, long and difficult, and is an ultimate goal to scientists working in quantum information science.

This fellowship proposes a smart route to large-scale quantum simulations that is intrinsically scalable, and can be implemented with manufacturable technologies. The project aims to simulate quantum physical models at a scale that surpasses the capabilities of conventional computers. This is possible because a mapping has been identified between an established model for the quantum vibrational behaviour of molecules, which cannot be simulated with a conventional computer, and the description of photons in manufacturable optical chips. By injecting ensembles of single photons into a versatile optical chip, the evolution of a large molecule can be tracked.

The direction of the research is to then make improvements to the molecular mathematical model with a series of perturbations, which, in loose terms, are matched by perturbations to the optical circuits in the form of weak interactions between the photons. The difficulty in getting single photons to strongly interact is the main challenge for optical quantum computers. However, developing successive generations of devices that build up layers of weak interactions allows interesting and complex simulations to be performed on an increasingly tailored and accurate molecular model. As these devices progress, they will develop additional computational capabilities, such as the calculation of factors involved in chemical transitions and characteristic properties of biotic molecules.

Planned Impact

Beyond research circles that are already engaged with developing quantum technologies, industrial and technology sectors, the UK economy, and people in the wider society will experience significant impacts from the proposed research.

By investing £270M in developing quantum technologies, the UK government has recognised the possibilities for positive strategic impact on the national technological capability, and the unacceptable deficiency that would result from falling back in the race to realise the key demonstrators. This research will meet this national strategic requirement by targeting intrinsically efficient quantum simulations for a manufacturable technology, where classical computers fail. The international profile of UK technologies will experience a significant boost, as will the prospects for export, and the endorsement of government's investment, which will likely translate to a policy of deeper investment.

The impact from the arrival of physical devices with algorithmic capabilities that are impossible to match by any upgrade or improvement to classical technology will be felt across computer science and the ICT sector, including high performance computing and software developers. Stakeholders in these areas are likely to want early exposure to the new quantum technology. As a key demonstrator, the proposed devices will be available to computer scientists and programmers as a testbed for the development of quantum coding languages.

New applications for industrial quantum chemists will be related to calculation of currently intractable factors involved in predicting electronic transitions. The simulators will engage biologists in the effort to understand the role of quantum mechanics in biology, and to simulate proposed quantum models for biotic molecules and proteins. With lattice vibration models central to condensed matter, physicists in this area, together with chemists and biologists, can explore further simulator applications by working wth prototypical devices and further engage in the development of quantum technologies.

Growth should be anticipated in the photonics technologies industrial sector, as quantum photonics technologies translate from the lab to find applications in the wider world. An IP portfolio for photonic quantum technologies is expected from this research, with guidance from the University of Bristol Research Commercialisation Team. I have previous experience of this process with a joint quantum communication patent with Nokia.

For people in the wider society, the profile of quantum information processors will be catapulted into the collective consciousness in a way that can only happen with a tangible physical demonstrator. The new capability will motive the inclusion of quantum information science in the classroom, particularly as part of traditional IT lessons. The scientific cultural landscape of the general public in the UK, particularly among popular science enthusiasts, will buzz with excitement as the research outputs are reported by mainstream media. There will follow a desire to understand something of the new technological capabilities and the underlying quantum physics. Interest in studying physics beyond school level should be boosted.
 
Title MoleculeArt 
Description An acrylic painting by Eleonora Martorana interpreting our programmable photonic chip as an old fashioned movie projector. 
Type Of Art Artwork 
Year Produced 2018 
Impact Widespread engagement and coverage 
 
Title VideoMolecules2018 
Description Our data re-interpreted as videos of molecules. 
Type Of Art Film/Video/Animation 
Year Produced 2018 
Impact Presented on Youtube, at conferences, and to industry. 
 
Description In "Simulating molecular quantum dynamics with photonics" we develop and demonstrate new methods for simulating key molecular processes with a programmable photonic chip. In "Experimental Quantum Hamiltonian Learning", we demonstrated that a quantum simulator can learn whether the models we use to describe the physical world are well founded. For large models, an ordinary classical simulator is not powerful enough to do this in a reasonable time frame, for example. In "Direct Dialling of Haar Random Unitary Matrices" we provide a very practical recipe for implementing random circuitry, which can be much more troublesome than one might expect - true randomness take careful thought. In "Classical algorithms for boson sampling" we showed that our understanding of the point at which a rudimentary quantum simulator outperforms a classical computer was wrong. In "Multidimensional quantum entanglement with large-scale integrated optics" we set a new standard for the number of components integrated into a high performance chip.
Exploitation Route The national program will develop out molecular simulation techniques for industrial applications. New characterisation methods for quantum systems - a key challenge for all large scale quantum simulators or computers. New classical algorithms to verify the operation of quantum simulators and motivating other groups to take a more rigorous approach to understanding the point at which a quantum simulator provides a computational advantage. New possibilities for large scale photonic information processing.
Sectors Chemicals,Digital/Communication/Information Technologies (including Software),Energy,Environment,Pharmaceuticals and Medical Biotechnology

 
Description The findings in "Simulation of molecular quantum dynamics with photonics" published in Nature are underpinning for the next phase of the National Quantum Computing and Simulation Hub. The findings in the paper "Experimental Quantum Hamiltonian Learning" have led to new ways to program quantum simulators using machine learning techniques. These could find application in simulating the control of molecules and impact pharmaceuticals and materials design. The findings from the paper "Classical algorithms for boson sampling" have motived industrial groups at IBM and Google to understand the classical limits for simulating their proposed quantum machines. The findings in "Multidimensional quantum entanglement with large-scale integrated optics" have motivated new quantum communication schemes. The findings in "Generating and sampling from quantum states of light" have shown that generating large numbers of photons is possible with on-chip photonics.
First Year Of Impact 2018
Sector Chemicals,Pharmaceuticals and Medical Biotechnology,Other
Impact Types Economic,Policy & public services

 
Description Capri2017
Geographic Reach Europe 
Policy Influence Type Participation in a advisory committee
Impact Bilateral meeting to strengthen UK-Italian research ties in the context of Brexit. A major focus for the meeting was strengthening UK research ties with Italy in quantum technologies, an area in which Bristol is a world leader. Influenced policy of Universities UK International.
 
Description CDT-Chadwick
Amount £70,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2017 
End 10/2020
 
Description CDT-Flynn
Amount £70,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2017 
End 10/2020
 
Description CDT-Koteva
Amount £70,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2017 
End 10/2020
 
Description CDT-Wakefield
Amount £70,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2017 
End 10/2020
 
Description DTA-Mainos
Amount £70,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2017 
End 03/2021
 
Description DTA-Yard
Amount £70,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2017 
End 03/2021
 
Description Hybrid discrete/continuous variables boson sampling with the inclusion of quantum memories
Amount £80,000 (GBP)
Funding ID 1798430 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2016 
End 09/2020
 
Description Quantum Hamiltonian Learning as a bridge from ideal physical models to real experiments.
Amount £80,000 (GBP)
Funding ID 1798799 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 09/2016 
End 09/2020
 
Description Quantum Lagrangian Learning
Amount £80,000 (GBP)
Funding ID 1798920 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2016 
End 09/2020
 
Description Simulating Models on the boundary of quantum physics
Amount £80,000 (GBP)
Funding ID 1800911 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2016 
End 09/2020
 
Description Using machine learning to program a quantum simulator in integrated photonics
Amount £80,000 (GBP)
Funding ID 1943275 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 09/2017 
End 03/2021
 
Title MoleculeSim 
Description New techniques for photonic quantum simulation of molecular dynamics 
Type Of Material Improvements to research infrastructure 
Year Produced 2017 
Provided To Others? No  
Impact A new class of quantum simulator. (Paper under review) 
 
Title CBS 
Description Numerical data collected from simulations of classical boson sampling 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact The data set supports our Nature Physics publication on this work 
URL https://data.bris.ac.uk/data/dataset/2ok605tzyel9o20lpmz2kky7wd
 
Description European Quantum Flagship 
Organisation University of Vienna
Country Austria 
Sector Academic/University 
PI Contribution Proposal submitted, led by Vienna. I am the Bristol PI
Collaborator Contribution Coordinated by Vienna
Impact Proposal under review
Start Year 2018
 
Description Hefei 
Organisation University of Science and Technology of China USTC
Department Hefei National Laboratory for Physical Sciences at the Microscale
Country China 
Sector Charity/Non Profit 
PI Contribution Developed a new theory for quantum tomography applicable to the types of experiments by colleagues at USTC in Hefei, China.
Collaborator Contribution They successfully carried out the experiment.
Impact A paper has been written and submitted.
Start Year 2016
 
Description ML-ITN 
Organisation Sapienza University of Rome
Country Italy 
Sector Academic/University 
PI Contribution Having been invited by Rome to join a proposal for a Maire Curie training network on Machine Learning, we submitted a proposal for a PhD project.
Collaborator Contribution Rome are leading the bid.
Impact Proposal re-submitted for 2018
Start Year 2016
 
Description Muenster Devices 
Organisation University of Münster
Country Germany 
Sector Academic/University 
PI Contribution We are designing and testing quantum photonic devices.
Collaborator Contribution Muenster are fabricating the devices
Impact In initial testing phase.
Start Year 2019
 
Description Photonic circuit design, fab and test 
Organisation University of Southampton
Country United Kingdom 
Sector Academic/University 
PI Contribution Design of devices for fabrication at Southhampton. Testing of devices at Bristol
Collaborator Contribution Fabrication of silicon nitride circuits
Impact Devices fabricated and tested
Start Year 2016
 
Description Photonic simulation theory 
Organisation University Libre Bruxelles (Université Libre de Bruxelles ULB)
Country Belgium 
Sector Academic/University 
PI Contribution A new theory on realising random unitary operations with photonic circuits.
Collaborator Contribution Theoretical contribution
Impact Two outcomes. 1We published a paper in NJP (http://iopscience.iop.org/article/10.1088/1367-2630/aa60ed/meta), 2. My collaborator will join my team as a postdoc.
Start Year 2016
 
Description Quantera 
Organisation Charles University
Country Czech Republic 
Sector Academic/University 
PI Contribution Proposed and led a submission to the EU Quantera call
Collaborator Contribution Contributed to the proposal - initial stage
Impact Proposal was not successful at final stage.
Start Year 2017
 
Description Quantera 
Organisation University Libre Bruxelles (Université Libre de Bruxelles ULB)
Country Belgium 
Sector Academic/University 
PI Contribution Proposed and led a submission to the EU Quantera call
Collaborator Contribution Contributed to the proposal - initial stage
Impact Proposal was not successful at final stage.
Start Year 2017
 
Description Quantera 
Organisation University of Cologne
Country Germany 
Sector Academic/University 
PI Contribution Proposed and led a submission to the EU Quantera call
Collaborator Contribution Contributed to the proposal - initial stage
Impact Proposal was not successful at final stage.
Start Year 2017
 
Description Quantera 
Organisation University of Southampton
Country United Kingdom 
Sector Academic/University 
PI Contribution Proposed and led a submission to the EU Quantera call
Collaborator Contribution Contributed to the proposal - initial stage
Impact Proposal was not successful at final stage.
Start Year 2017
 
Description Quantera 
Organisation University of the Basque Country
Country Spain 
Sector Academic/University 
PI Contribution Proposed and led a submission to the EU Quantera call
Collaborator Contribution Contributed to the proposal - initial stage
Impact Proposal was not successful at final stage.
Start Year 2017
 
Description Quantum Field Learning 
Organisation University of Ulm
Country Germany 
Sector Academic/University 
PI Contribution I have supported the collaboration of my colleague with an experimental team in Ulm. We have provided new theories of machine learning to learn magnetic fields using the Ulm team's NV diamond experiments.
Collaborator Contribution Experimental sets ups and expertise.
Impact Paper in prep
Start Year 2017
 
Company Name DUALITY QUANTUM PHOTONICS LTD 
Description Duality Quantum Photonics will build special purpose quantum simulators in integrated photonics. 
Year Established 2020 
Impact We have raised ~£0.5M from Innovate UK
 
Description Amsterdam2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Represented the UK at Quantum Europe 2016 in Amsterdam speaking at the launch of the European flagship for quantum technologies
Year(s) Of Engagement Activity 2016
 
Description BilbaoMar2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Quantum Machine Learning and Biomimetic Quantum Technologies [invited talk]
Bilboa, Spain 19th - 23rd March 2018
Year(s) Of Engagement Activity 2018
 
Description BirminghamSept2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Photon18 by the Institute of Physics [invited plenary]
Birmingham, UK 3rd - 7th September 2018
Year(s) Of Engagement Activity 2018
 
Description BristolApr2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Bristol Quantum Information and Technologies Workshop [invited talk]
Bristol, UK 18th - 20th April 2018
Year(s) Of Engagement Activity 2018
 
Description BristolJuly2018 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact International Workshop in Analogue Experimentation [invited talk]
Bristol, UK 16th - 17th July 2018
Year(s) Of Engagement Activity 2018
 
Description Capri2017 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Led UK delegation representing research in quantum technologies for UK-Italian bilateral meeting, held in Capri
Year(s) Of Engagement Activity 2017
 
Description China2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited talk on my research at conference in Zhuhai, China for quantum information science
Year(s) Of Engagement Activity 2017
 
Description FestivalOfScience2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Talk on the history of quantum technologies at the Festival of Physics in Bristol (March 2017)
Year(s) Of Engagement Activity 2017
 
Description GrenobleFeb2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact European Quantum Technology Conference:
The 1st international conference of the QT Flagship [invited plenary]
Grenoble, France 18th - 22nd February 2019
Year(s) Of Engagement Activity 2019
 
Description HongKongAug2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact CLEO Pacific Rim 2018 [invited talk]
Hong Kong, 29th July - 3rd August 2018
Year(s) Of Engagement Activity 2018
 
Description ParisOct2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact International Conference on Integrated Quantum Photonics [invited talk]
Paris, France 15th - 17th October 2018
Year(s) Of Engagement Activity 2018
 
Description ParisSept2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Japan-EU workshop: Advanced Quantum Technology for Future Innovation [invited talk]
Paris, France 3rd - 4th September 2018
Year(s) Of Engagement Activity 2018
 
Description Public event in Cambridge: Quantum Computing: The Truths, the Myths, and the Challenges 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Public information event with international panel of leading experts in Quantum Computing.
Year(s) Of Engagement Activity 2020
 
Description QIL2019 
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 Took part in Bristol's Quantum Innovation Lab, which explores the translation of quantum technologies from academia to industry. I engaged with representatives from Siemens.
Year(s) Of Engagement Activity 2019
 
Description RomeApr2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Quantum Information and Measurement V:
Quantum Technologies by the Optical Society [invited talk]
Rome, Italy 4th - 6th April 2019
Year(s) Of Engagement Activity 2019
 
Description SingaporeJune2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Advances in Quantum Engineering [invited talk]
Singapore 24th - 27th June 2018
Year(s) Of Engagement Activity 2018
 
Description Swansea2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Invited research talk at Swansea University
Year(s) Of Engagement Activity 2016
 
Description ThalesReview 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Headed a consultancy project including report and workshop on the impact of quantum computing to Thales (multinational tech company)
Year(s) Of Engagement Activity 2018
 
Description Turin2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited talk at Quantum Optics conference in Turin
Year(s) Of Engagement Activity 2017