How does macroscopic disorder come from microscopic order?
Lead Research Organisation:
University of York
Department Name: Physics
Abstract
Professor D'Amico's project focusses on introducing a DFT approach to quantum thermodynamics enabling an investigation into the many-body work function. Quantum mechanics is based on the Schrodinger equation, which predicts reversibility, however thermodynamics of macroscopic systems states fundamentally that entropy always tends to increase. The question to be investigated is how does macroscopic disorder come from microscopic order? To begin to solve this, the work distribution function needs to be determined, however it has not been solved for multiple spin systems. The DFT approach allows for investigations of multiple spin to take place by giving a more accessible quantity to model and experimentally test, the density. Therefore using the DFT approach to quantum thermodynamics will provide a simpler experimental protocol when investigating many body interacting systems which should be more scalable than current methods. The project will also introduce the use of metric spaces as a tool for practical analysis of experimental results. Having already worked with DFT and metric spaces in my MPhys project, I can really appreciate the usefulness of DFT, making complex calculations more manageable, and the new perspectives and information the metrics can give on data.
People |
ORCID iD |
| Irene D'Amico (Primary Supervisor) | |
| Amy Skelt (Student) |
Publications
Skelt A
(2018)
Metrics for Two Electron Random Potential Systems
in Brazilian Journal of Physics
Skelt A
(2018)
Measuring adiabaticity in nonequilibrium quantum systems
in Physical Review A
Skelt A
(2019)
Many-body effects on the thermodynamics of closed quantum systems
in Journal of Physics A: Mathematical and Theoretical
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509802/1 | 01/10/2016 | 31/03/2022 | |||
| 1799688 | Studentship | EP/N509802/1 | 01/10/2016 | 30/09/2019 | Amy Skelt |
| Description | We have shown how measuring the distances of properties in quantum systems enables us to characterise the evolution of the system as slow enough to be considered adiabatic or not. This new technique is simple and visual, where the user need only plot a line on a graph to see how close the evolution is to an adiabatic evolution. We have then extended this technique to systems at temperature, which is especially important given most practical applications for adiabatic evolutions are at temperature (even if it is a very cold temperature). This research gives valuable insight into quantum systems, and can opens up questions into a fundamental theorem in Density Functional Theory (DFT - a theory which is used widely in condensed matter physics and chemistry to model molecules); namely it questions the nature of the Hohenberg-Kohn mapping (which shows a system can be considered using the electron density in place of the more complicated wave function) in metric spaces (which look at the distances between objects). We have also developed a new technique for using DFT to help approximate quantum thermodynamic properties in many-body quantum systems. This technique is computationally cheap but surprisingly accurate in a wide range of systems. This method can be extended to larger system sizes, where exact calculations cannot be performed. This allows one to determine the regime/system where maximum work can be achieved. From this, there is the ability to generate more efficient quantum devices, as one can find the parameters which maximise work whilst minimising entropy. |
| Exploitation Route | Adiabatic quantum computing is very important for advancing quantum technologies, but for this to take place effectively, we need to know how to characterise an adiabatic evolution in a quantum system. Our work here is able to do this in a graphical way, and can therefore be taken forward and used by those working with adiabatic quantum computers to ensure their computations are indeed adiabatic. This leads to more stable calculations. Quantum devices are vital for developing new technologies, but we need to know how to run the devices most efficiently. Our DFT-inspired technique of approximating quantum work and entropy production can be used by those developing these devices, allowing them to calculate the parameters where their devices are most efficient. Without an approximation, this would not be possible to do for many-body systems due to their complexity. Future research can refine and develop more sophisticated approximations using the method outlined in our work. |
| Sectors | Other |
| Description | CNPq through the PVE scheme (grant no. 401414/2014-0) |
| Amount | R$ 6,000 (BRL) |
| Organisation | National Council for Scientific and Technological Development (CNPq) |
| Sector | Public |
| Country | Brazil |
| Start | 10/2017 |
| End | 11/2017 |
| Description | W W Smith |
| Amount | £1,500 (GBP) |
| Organisation | University of York |
| Sector | Academic/University |
| Country | United Kingdom |
| Start | 10/2019 |
| End | 03/2020 |
| Description | Applying metrics to quantum systems with random potentials |
| Organisation | University of York |
| Department | Department of Physics |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | I performed the calculations of the distance measures for the range of quantum systems we developed, and analysed the results. I was also the main author writing the paper. Professor Irene D'Amico brought her expertise on both quantum many-body systems and metric spaces, as well as helped in writing the paper. |
| Collaborator Contribution | Professor Rex Godby's group provided their iDEA code for the calculations of the quantum systems, and Professor Godby provided his expertise throughout the project and in writing the paper. |
| Impact | This research was published in Physics Review A (DOI: 10.1103/PhysRevA.98.012104) demonstrating how distances measures (metrics) can be used to determine if a quantum system is being evolved slowly enough to be characterised as adiabatic. This is important for adiabatic quantum computing. This research also demonstrated that there is a linear relationship between the distances of densities and the distances of wave functions (DOI: 10.1007/s13538-018-0589-1) which is important for understanding one of the main theorems in density functional theory, which is used to model a wide range of systems, from a few atoms to large molecules. |
| Start Year | 2016 |
| Description | Approximations for quantum thermodynamic properties |
| Organisation | Universidade de São Paulo |
| Department | Institute of Physics in Sao Carlos |
| Country | Brazil |
| Sector | Academic/University |
| PI Contribution | After engaging in discussions with Krissia Zawadkzi, I adjusted her code to perform new calculations approximating quantum thermodynamic properties. |
| Collaborator Contribution | Krissia Zawadkzi provided an incredibly versatile code of her own creation, as well as engaging in many useful discussions evaluating our work and results and providing useful insight. |
| Impact | There are at least two papers currently being written on the results of this work, demonstrating cheap but accurate approximations for quantum thermodynamic properties, as well as solving the behaviours of these properties exactly. |
| Start Year | 2017 |
| Description | CMP Group Away Day (York) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Postgraduate students |
| Results and Impact | The condensed matter physics group held an aways day where we all presented our current work and discussed the direction of the group and its research. Useful conversations were had which helped direct research |
| Year(s) Of Engagement Activity | 2019 |
| Description | Density Functional Theory meets Quantum Information theory (Sao Paulo, Brazil) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Presented a poster at the workshop to academics and post graduate students. The work presented was showing the distance measures for quantum systems to characterise adiabaticity. Good discussions were had and inquiries made to see further research once published. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Nano-scale quantum optics workshop (Prague) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Presented a poster to academics at the workshop, describing the use of distance measures for characterising adiabatic evolutions in quantum systems, with uses in quantum technologies and for developing understanding of well-known theories. Useful discussions were had, prompting further thought about the work. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Nano-scale quantum optics workshop (Varenna, Italy) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Presented a poster at a school for post graduate students from all over Europe. The work was showing the usefulness of using distance measures for characterising adiabatic evolutions of quantum systems. Interesting discussions and questions were had. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Northern Quantum Meeting 2019 (Leeds) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Postgraduate students |
| Results and Impact | Presented a talk on the latest results of this work to post graduate students from universities in the north of the UK, showing cheap but accurate approximations to quantum thermodynamic properties for use in quantum technologies. Useful questions and discussions afterwards were had. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Post graduate conference 2017 (York) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Postgraduate students |
| Results and Impact | Work on using distance measures to characterise an adiabatic evolution of a quantum system was presented in a talk to peers at the university. Interesting discussion was had with one peer after the session, who seemed interested in the research. |
| Year(s) Of Engagement Activity | 2017 |
| Description | QuAMP (Birmingham) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | Researchers and businesses from Quantum, Atomic, and Molecular physics backgrounds came together to show their current work and discuss future progressions. Potential collaborations were discussed, and much interest was had in the work from this award. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Quantum Dynamics of Disordered Interacting Systems (Trieste) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Presented a poster to academics and post graduate students on the work with the metrics (distance measures). Interesting discussions were had, especially talking to experimental physicists about how they perform calculations. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Quantum Roundabout 2018 (Nottingham) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Presented a talk on the latest results from the work relating to this award to postgraduates and post docs; looking at cheap but accurate approximations for quantum thermodynamic properties which can be used in quantum technologies. There were interesting questions after the talk, inquiring about further applications to quantum systems. |
| Year(s) Of Engagement Activity | 2018 |
| Description | Quantum Thermodynamics Conference 2019 (Helsinki) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Other audiences |
| Results and Impact | The quantum thermodynamics community came together to present their recent work, and spark lively discussions about the future direction of the field. |
| Year(s) Of Engagement Activity | 2019 |