Controlled long-range coherent coupling of solid-state qubits
Lead Research Organisation:
CARDIFF UNIVERSITY
Department Name: School of Physics and Astronomy
Abstract
Information technology has gained importance over the last 20 years due to the improving user-friendliness, capability and affordability of the related hardware and software. Today, the internet is the dominant information source for a majority of society, and is likely to be the dominant way of communication within the next decade. This has revolutionised the way society works, improving efficiency and personal choice. The underlying technology is based on classical computing, which faces fundamental limits of its power consumption dictated by the thermodynamics of the implemented classical algorithms. Quantum computing is seen as the next generation technology to augment classical computing, enabling new types of algorithms for more efficient and rapid processing.
This proposal is underpinning this next generation technology. It aims to develop and characterise controlled coherent and incoherent long-range coupling between qubits. The experimental realisation in a quantum dot - optical cavity system integrated with semiconductor technology is one of the promising routes for the implementation of quantum information technology. The physical mechanisms of the coherent coupling researched in this project have however a wide range of importance across physics and biosciences, beyond the specific material system and application investigated.
This proposal is underpinning this next generation technology. It aims to develop and characterise controlled coherent and incoherent long-range coupling between qubits. The experimental realisation in a quantum dot - optical cavity system integrated with semiconductor technology is one of the promising routes for the implementation of quantum information technology. The physical mechanisms of the coherent coupling researched in this project have however a wide range of importance across physics and biosciences, beyond the specific material system and application investigated.
Planned Impact
The proposed research will characterise and develop controlled coherent and incoherent long-range coupling between qubits. The physical mechanisms of the coherent coupling researched in this project have also a wide range of importance across physics and biosciences.
Economy
The coherent coupling technology resulting from the research will enable applications in quantum information processing, which is expected to revolutionise information and communication technology (ICT) over the next 30 years, with the related impact in the high-tech industry. The optical HSI technique developed further within this project has the potential to be commercialised as a general characterisation instrument of coherence of individual quantum systems.
Society
ICT has gained importance over the last 20 years in society due to the improving user-friendliness, capability and affordability of the related hardware and software. Today, the internet is the dominant information source for a majority of society, and is likely to be the dominant way of communication within the next decade. This has revolutionised the way society works, improving efficiency and personal choice. The underlying technology is based on classical computing, which faces fundamental limits of its power consumption limited by the thermodynamics of the implemented classical algorithms. Quantum computing is seen as the next generation technology to augment classical computing, enabling new types of algorithms for more efficient and rapid processing. This present proposal is part of the development of this next generation technology. We will engage in outreach activities to raise the awareness and enthusiasm in the public for these developments.
Economy
The coherent coupling technology resulting from the research will enable applications in quantum information processing, which is expected to revolutionise information and communication technology (ICT) over the next 30 years, with the related impact in the high-tech industry. The optical HSI technique developed further within this project has the potential to be commercialised as a general characterisation instrument of coherence of individual quantum systems.
Society
ICT has gained importance over the last 20 years in society due to the improving user-friendliness, capability and affordability of the related hardware and software. Today, the internet is the dominant information source for a majority of society, and is likely to be the dominant way of communication within the next decade. This has revolutionised the way society works, improving efficiency and personal choice. The underlying technology is based on classical computing, which faces fundamental limits of its power consumption limited by the thermodynamics of the implemented classical algorithms. Quantum computing is seen as the next generation technology to augment classical computing, enabling new types of algorithms for more efficient and rapid processing. This present proposal is part of the development of this next generation technology. We will engage in outreach activities to raise the awareness and enthusiasm in the public for these developments.
Organisations
- CARDIFF UNIVERSITY (Lead Research Organisation)
- IBM (Collaboration)
- University College Cork (Collaboration, Project Partner)
- NEEL Institute (Collaboration)
- University of Bristol (Collaboration)
- University of Sheffield (Project Partner)
- Technical University of Munich (Project Partner)
- École Polytechnique Fédérale de Lausanne (Project Partner)
Publications
Weiss T
(2018)
How to calculate the pole expansion of the optical scattering matrix from the resonant states
in Physical Review B
Sehmi H
(2020)
Applying the resonant-state expansion to realistic materials with frequency dispersion
in Physical Review B
Scarpelli L
(2019)
99% beta factor and directional coupling of quantum dots to fast light in photonic crystal waveguides determined by spectral imaging
in Physical Review B
Scarpelli L
(2017)
Resonantly excited exciton dynamics in two-dimensional MoSe 2 monolayers
in Physical Review B
Naeem A
(2015)
Giant exciton oscillator strength and radiatively limited dephasing in two-dimensional platelets
in Physical Review B
Muljarov EA
(2018)
Resonant-state expansion for open optical systems: generalization to magnetic, chiral, and bi-anisotropic materials.
in Optics letters
Muljarov E
(2017)
Comment on "Normalization of quasinormal modes in leaky optical cavities and plasmonic resonators"
in Physical Review A
Description | We have measured the beta factor and the circularity of the emission of quantum dots in a photonic crystal waveguide. For the first time, this has been done using directly the emission power measurements, removing the uncertainty of lifetime mesurements used in the past. beta factors of above 95% have been measured in the fast light regime, which is a step towards using these devices in quantum information processing on chip. We have measured the coherent dynamics of excitons in colloidal quantum dot systems of InP/ZnSe, and perovskite materials. These properties are important for the use of these materials in quantum technology, and as phophors in displays. The phonon-assisted dephasing of quantum dots strongly coupled to optical cavities was treated theoretically on a rigorous basis using a trotter decomposition methods, suited for all regimes of coupling strengths A method to measure the quantum dot size, the material deformation potential, and the temperature using a fit to the emission lineshape was developed - this can be important for temperature sensors and material characterization |
Exploitation Route | The high beta factor and directional emission can be employed to build quantum photonic circuits. The long dephasing times found in the colloidal quanum dots highlights them for use in quantum technologies. The rigorous theory of quantum dot / cavity / phonon coupling allows to predict and design the properties of such systems in quantum technology. The method to measure the quantum dot size, the material deformation potential, and the temperature can be used for temperature sensors and material characterization. |
Sectors | Digital/Communication/Information Technologies (including Software) Electronics |
Description | The resonant state expansion electromagnetic theory and simulation method developed within this project is now being used to improve the design of photonic systems. The method is benefitting the photonics and ICT industry in the follwing applications - design of nanostructured on-chip laser sources such as vertical cavity semiconductor lasers (VCSELs) - design of high quality factor sensing microcavities for enviromental and biosensing - design of waveguides and couplers for integrated photonics |
First Year Of Impact | 2021 |
Sector | Digital/Communication/Information Technologies (including Software) |
Impact Types | Economic |
Description | 4PI Two-photon Lithography for Isotropic 3D Nanostructure Fabrication |
Amount | £771,658 (GBP) |
Funding ID | EP/R009147/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 01/2018 |
End | 12/2021 |
Description | Forster transfer in quantum dots |
Amount | £80,000 (GBP) |
Organisation | Cardiff University |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2020 |
End | 03/2024 |
Description | Multiphoton Microscopy and Ultrafast Spectroscopy: Imaging meets Quantum (MUSIQ) |
Amount | € 4,034,447 (EUR) |
Funding ID | 812922 |
Organisation | Marie Sklodowska-Curie Actions |
Sector | Charity/Non Profit |
Country | Global |
Start | 03/2019 |
End | 03/2023 |
Description | Quantum coherence in single biomolecules measured by multidimensional optical micro-spectroscopy |
Amount | £80,000 (GBP) |
Organisation | Cardiff University |
Department | School of Physics and Astronomy |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2021 |
End | 03/2025 |
Description | Responsive Mode |
Amount | £1,200,000 (GBP) |
Funding ID | EP/P011470/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2017 |
End | 03/2020 |
Description | Solid State Superatoms |
Amount | £653,988 (GBP) |
Funding ID | EP/P011470/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 04/2017 |
End | 04/2022 |
Title | Resonant-state expansion of three-dimensional open optical systems: Light scattering |
Description | The data contains calculated reflection and scattering cross-section coefficients, as well as related accuracies. |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Title | Resonantly excited exciton dynamics in two-dimensional MoSe2 monolayers |
Description | The data contains results of four-wave mixing and transmission experiments on MoSe2 monolayers and their analysis. |
Type Of Material | Database/Collection of data |
Year Produced | 2017 |
Provided To Others? | Yes |
Description | Bristol / Oulton |
Organisation | University of Bristol |
Department | Bristol Research Unit |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We have measured the directional emission of the quantum dots in the provided samples, and coordinated the interpretation of results and publication. |
Collaborator Contribution | The group of Ruth Oulton has contributed to the a collaboration on quantum dot emission in photonic crystal waveguides which lead to the publication [10.1103/PhysRevB.100.035311]. A sample, fabricated in the University of Wurzburg during a previous project, was made available for measurements. A PhD student in the group, Ben Lang, was working with us to develop electromagnetic simulations of the coupling and emission , and was running them on the compute cluster in Bristol. |
Impact | 10.1103/PhysRevB.100.035311 |
Start Year | 2017 |
Description | Cork Pelucchi |
Organisation | University College Cork |
Department | Department of Chemistry |
Country | Ireland |
Sector | Academic/University |
PI Contribution | Investigating dephasing and coherent coupling of vertically coupled quantum dots |
Collaborator Contribution | Growth and characterization of bespoke vertically coupled quantum dots for our investigations |
Impact | None yet |
Start Year | 2015 |
Description | Grenoble Jacek Kasprzak |
Organisation | NEEL Institute |
Country | France |
Sector | Public |
PI Contribution | Contributed to Experimental Design and Software, Data interpreations and publications |
Collaborator Contribution | Made the measurements and analyzed data, prepared publications. |
Impact | 10.1088/2053-1583/aabc1c 10.1364/OPTICA.3.000377 10.1021/acs.nanolett.6b01060 10.1038/NPHOTON.2016.2 |
Start Year | 2015 |
Description | PHONSI IBM |
Organisation | IBM |
Department | IBM Research Zurich |
Country | Switzerland |
Sector | Private |
PI Contribution | Measurement of dephasing in peroskite quantum dots, analyzed data, contributed to publication |
Collaborator Contribution | Provided quantum dot sample, seconded PhD student, analyzed data, contributed to publication |
Impact | 10.1021/acs.nanolett.8b03027 |
Start Year | 2017 |
Title | Jitter correlation factorization |
Description | A software to factorize emission spectra of single quantum dots undergoing jitter into the temporal shift and the intrinsic lineshape. It ises Non-negative matrix factorization. The jitter can be additionally constrained using a multiple charge trap model, returning the respective energy shifts affected by each charged site. |
Type Of Technology | Software |
Year Produced | 2018 |
Impact | This software has been used to analyze data from different quantum dots (e.g. CdSe, InP, Perovskites), and will be made publically available this year, for other researchers or indistrial applications. |