Coherent quantum matter out of equilibrium - from fundamental physics towards applications

Lead Research Organisation: University College London
Department Name: Physics and Astronomy


The main aim of this project is to explore novel emergent phenomena in far from equilibrium quantum systems across different fields of research: from solid-state light-matter systems such as superconducting circuits, semiconductor micro-structures and quantum spins to ultra-cold atomic gases. Such cross-fertilisation between traditionally distinct areas is an essential ingredient in successful approach to understanding far from equilibrium collective processes together with the development of new efficient theoretical tools. EPSRC Physics Grand Challenge Survey has identified that "compared with that of equilibrium states, our understanding of states far from equilibrium is in its infancy" and that "on the theory front, there are significant gaps in knowledge, especially in quantum theory". At the same time the problem is "of considerable scientific and technological importance" and "with unforeseeable potential for applications". We shall study exotic quantum orders, bistabilities, pattern formation and other collective phenomena in state-of-the art light-matter systems. An important aspect of our project is to focus on systems, or their features, which in the longer run could lead to potential device applications: from polariton lasers and LEDs, low threshold optical switches, optical transistors, logic gates and finally polariton integrated circuits to quantum computers. Our theoretical analysis will be linked directly to the experiments of our project partners worldwide.

Planned Impact

Who will benefit from this research?
There are four classes of beneficiaries:
1) high-tech industry;
2) general public (science minded pupils, students, people interested in basic knowledge);
3) PDRAs and Warwick students;
4) other academics in PI's and other research areas.

How will they benefit from this research?
1 class) Superconducting qubits are leading the way in solid state quantum computing architectures with the largest potential for the transfer to industry. Semiconductor microcavities allow the observation of quantum effects at high up to room temperatures, and so the applications to new generation optoelectronic devices such as new light sources, polariton lasers, optical switches, transistors, logic gates, spintronic devices, etc. are widely discussed. Ultra-cold atomic gases are promising systems for precision measurements and high quality sensors with multi-disciplinary applications. Research towards understanding and controlling these systems brings potential applications closer to life, and in particular the research on polaritonic devices is directly part of the project.
2 class) The project is concerned with fundamental problems of non-equilibrium quantum physics, which have been identified in the UK as one of the main Physics Grand Challenges. Thus, if successful, this research will make its way to text-books, will broaden our general understanding of fundamental properties of matter, and be part of this exciting knowledge, which inspire imagination of new generation of students and encourage them to take physics degrees.
3 class) PDRAs positions, funded by this project, and PhD studentship committed by the Department, will provide excellent career development and training opportunities by combining analytical and numerical research with the direct interaction with experiment. The project will have a direct educational impact on Warwick undergraduates (final year project students) by exposing them to challenging theoretical problems, relevant to the state-of-the-art experiments. It will motivate them to continue onto research degrees and teach them skills relevant also in other type of employment (analysing data, comparing predictions of theoretical models to experimental results).
4 class) Outcomes of this research will benefit other researchers (both experimentalists and theorists) working in the areas of circuit QED, polariton BEC and superfluidity, solid-state condensation and coherence, superconductivity, ultra-cold atomic gases, on control problems in quantum mechanics, on general non-equilibrium field theory techniques, quantum optics, astrophysics, and nuclear physics (project or cold fermions). They will benefit from the results, and from the methods and numerical codes developed.

What will be done to ensure they have the opportunity to benefit from this research?
We will disseminate results at international conferences and will keep PI's web-pages updated with talks, preprints, publications and summaries. We will design separate pages with popular science explanations suitable for general public and students, and with technical details aimed at other academics and industry. We will also undertake some school outreach activities and will organise a multi-disciplinary workshop devoted to phenomena far from equilibrium in different quantum systems. If any commercially relevant outcomes appear as a result of this research, we will initiate discussions with Warwick Ventures, the University's technology transfer office, in order to properly exploit it. Also, the PI proposes to dedicate time to examine some of the possible industrial applications of our results and, in case of commercially relevant outcomes, to establish contact with industry.


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Ballarini D (2017) Macroscopic Two-Dimensional Polariton Condensates. in Physical review letters

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Cancellieri E (2014) Merging of vortices and antivortices in polariton superfluids in Physical Review B

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Comaron P (2018) Dynamical Critical Exponents in Driven-Dissipative Quantum Systems. in Physical review letters

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Dario Ballarini (2020) Directional Goldstone waves in polariton condensates close to equilibrium in Nature Communications volume

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Donati S (2016) Twist of generalized skyrmions and spin vortices in a polariton superfluid. in Proceedings of the National Academy of Sciences of the United States of America

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/K003623/1 30/06/2013 30/09/2013 £1,242,468
EP/K003623/2 Transfer EP/K003623/1 01/10/2013 29/06/2019 £1,222,168
Description extensive description can be found:
Exploitation Route quantum technologies, general knowledge of non-equilibrium matter
Sectors Digital/Communication/Information Technologies (including Software),Education,Electronics,Other

Description Quantera
Amount £1,470,890 (GBP)
Funding ID EP/R04399X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 02/2018 
End 02/2021
Description Daniele 
Organisation National Research Council
Department Nanotec - Institute of Nanotechnology
Country Italy 
Sector Public 
PI Contribution Helping to understand the outcomes of experiments. Modelling and simulating the physical phenomena experimentally studied in Lecce group.
Collaborator Contribution Performing experiments relevant to the theoretical work carried out in my group
Impact 1) Vortex and half-vortex stability in coherently driven spinor polariton fluid L. Dominici, J.M. Fellows, S. Donati, D. Ballarini, M. De Giorgi, F.M. Marchetti, B. Piccirillo, L. Marrucci, A. Bramati, G. Gigli, M.H. Szymanska, D. Sanvitto, Sci. Adv. 1, 11, e1500807 (2015) 2) Multicomponent polariton superfluidity in the optical parametric oscillator regime A. C. Berceanu, L. Dominici, I. Carusotto, D. Ballarini, E. Cancellieri, G. Gigli, M. H. Szymanska, D. Sanvitto, and F. M. Marchetti Phys. Rev. B 92, 035307 (2015) 3) Spontaneous vortex arrays in a parametrically driven polariton condensate J.O. Hamp, A.K. Balin, F.M. Marchetti, D. Sanvitto, M.H. Szymanska EPL (Europhysics Letters)110, 57006 (2015) 4) Merging of vortices and antivortices in polariton superfluids E. Cancellieri, T. Boulier, R. Hivet, D. Ballarini, D. Sanvitto, M. H. Szymanska, C. Ciuti, E. Giacobino, A. Bramati Phys. Rev. B 90, 214518 (2014) 5) Interaction-shaped vortex-antivortex lattices in polariton fluids R. Hivet, E. Cancellieri, T. Boulier, D. Ballarini, D. Sanvitto, F. M. Marchetti, M. H. Szymanska, C. Ciuti, E. Giacobino, A. Bramati Phys. Rev. B 90, 019904 (2014) 6)Control and ultrafast dynamics of a two-fluid polariton switch M. De Giorgi, D. Ballarini, E. Cancellieri, F. M. Marchetti, M. H. Szymanska, C. Tejedor, R. Cingolani, E. Giacobino, A. Bramati, G. Gigli, D. Sanvitto Phys. Rev. Lett. 109, 266407 (2012)
Start Year 2011
Description Iacopo 
Organisation University of Trento
Department Istituto Nazionale di Ottica Bose-Einstein Condensation (INO-CNR BEC) Centre
Country Italy 
Sector Academic/University 
PI Contribution we have developed numerical codes for truncated Wigner approach and applied to non-equilibrium phase transitions in light-matter systems
Collaborator Contribution expert on truncated Wigner methods, provided advice how to develop the method and numerical codes
Impact Non-equilibrium Berezinskii-Kosterlitz-Thouless Transition in a Driven Open Quantum System G. Dagvadorj, J. M. Fellows, S. Matyjaskiewicz, F. M. Marchetti, I. Carusotto, M. H. Szymanska Phys. Rev. X 5, 041028 (2015)
Start Year 2014
Description Madrid 
Organisation Autonomous University of Madrid
Department The Department of Physics of Materials
Country Spain 
Sector Academic/University 
PI Contribution Theoretical work in the area of polariton superfluidity. Suggesting experiments to observe theoretically predicted phenomena. Analysis of experimental results. Modelling of experimental conditions and simulations for experiments
Collaborator Contribution Performing relevant experiments. Theoretical work in Dr Marchetti group.
Impact 1)Frictionless flow in a binary polariton superfluid E. Cancellieri, F. M. Marchetti, M. H. Szymanska, D. Sanvitto, C. Tejedor Phys. Rev. Lett. 108, 065301 (2012) 2)Onset and Dynamics of Vortex-Antivortex Pairs in Polariton Optical Parametric Oscillator Superfluids G. Tosi, F. M. Marchetti, D. Sanvitto, C. Anton, M. H. Szymanska, A. Berceanu, C. Tejedor, L. Marrucci, A. Lematre, J. Bloch, L. Vina Phys. Rev. Lett. 107, 036401 (2011) 3) Multistability of a two component exciton-polariton fluid E. Cancellieri, F. M. Marchetti, M. H. Szymanska, C. Tejedor Phys. Rev. B 83, 214507 (2011) 4) Superflow of resonantly driven polaritons against a defect E. Cancellieri, F. M. Marchetti, M. H. Szymanska, C. Tejedor Phys. Rev. B 82, 224512 (2010) 5) Propagating wavepackets and quantised currents in coherently driven polariton superfluids M. H. Szymanska, F. M. Marchetti, D. Sanvitto Phys. Rev. Lett. 105, 236402 (2010) 6) Spontaneous and Triggered Vortices in Polariton Optical-Parametric-Oscillator Superfluids F. M. Marchetti, M. H. Szymanska, C. Tejedor, D. M. Whittaker Phys. Rev. Lett. 105, 063902 (2010) 7) Persistent currents and quantised vortices in a polariton superfluid D. Sanvitto, F. M. Marchetti, M. H. Szymanska, G. Tosi, M. Baudisch, F. P. Laussy, D. N. Krizhanovskii, M. S. Skolnick, L. Marrucci, A. Lemaitre, J. Bloch, C. Tejedor, L. Vina Nature Physics 6, 527 (2010)
Start Year 2009
Description Rob 
Organisation Imperial College London
Department Department of Physics
Country United Kingdom 
Sector Academic/University 
PI Contribution theoretical analysis related to photon BEC
Collaborator Contribution theoretical (from the experimentalist perspective) and experimental analysis related to photon BEC
Impact Interactions in dye-microcavity photon condensates and the prospects for their observation R. A. Nyman and M. H. Szymanska Phys. Rev. A 89, 033844 (2014)
Start Year 2013
Description Yamamoto 
Organisation Stanford University
Department E. L. Ginzton Laboratory
Country United States 
Sector Academic/University 
PI Contribution analysis of experimental data, theoretical description of experimental observations, interpretation of experimental findings
Collaborator Contribution experiments on spatial coherence of polariton condensate
Impact Power-law decay of the spatial correlation function in exciton-polariton condensates Georgios Roumpos, Michael Lohse, Wolfgang H. Nitsche, Jonathan Keeling, Marzena Hanna Szymanska, Peter B. Littlewood, Andreas Löffler, Sven Höfling, Lukas Worschech, Alfred Forchel, and Yoshihisa Yamamoto Proc. Nat. Acad. Sci 109, 6467 (2012)
Start Year 2010
Description AMOPP open day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Undergraduate students
Results and Impact AMOPP open day to show research activities for prospective PhD students
Year(s) Of Engagement Activity 2013,2014,2015
Description IOP public lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact IOP Gareth Roberts Memorial Lecture - Designing a world from light
Year(s) Of Engagement Activity 2016
Description TechGirls Outreach Program 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Workshop on Quantum Technologies
Year(s) Of Engagement Activity 2018