Novel superfluid phenomena in semiconductor microcavities

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


Superfluidity is one of the most remarkable consequences of macroscopic quantum coherence in interacting condensed matter systems, and manifests itself in a number of fascinating effects, such as for example dissipationless flow of a superfluid via obstacles, quantised circulation, and metastable persistent currents. First observed in liquid Helium in 1937, it is closely related to the phenomena of Bose-Einstein condensation (BEC), and to the Bardeen-Cooper-Schrieffer (BCS) collective state of fermions, which is responsible for superconductive behaviour of some materials.The phenomenon of macroscopic coherence and superfluidity is not restricted to systems close to thermodynamic equilibrium, such as liquid Helium, superconductors and ultra-cold atomic gases. It has also been recently observed in systems far from equilibrium, where a steady-state is obtained by a dynamical balance of driving and losses. Semiconductor microcavities currently play a leading role in the study of non-equilibrium superfluidity. Strong interactions between confined light and bosonic excitations in the semiconductor (called excitons) lead to new quasi-particles - microcavity polaritons, in which interactions can be manipulated externally by changing the driving power and the energy detuning between photons and excitons, and where the matter component can be accurately probed by measuring the properties of the emitted light.An additional advantage of semiconductor microcavities is that the temperatures for BEC and superfluidity in current experiments are of the order of 10K, and are only limited by relatively small dipole interactions between excitons and photons in GaAs. Other materials, such as GaN, have already hosted polariton lasing at room temperature, and it is now only a question of technological progress in manufacturing samples of a better quality (less of the inhomogeneous disorder) for polariton BEC and superfluidity to be realised at room temperature. Quantum collective effects at such high temperatures are likely to lead to device applications, for example in quantum storage and computation, and for transporting light-matter pulses without loss over macroscopic distances.However, properties which characterise non-equilibrium superfluids in dissipative and driven quantum systems are fundamentally different compared to superfluids in thermal equilibrium, and thus we are faced with an exciting opportunity to discover and explore brand-new physical phenomena. This project is aimed at exploring novel superfluid properties of non-equilibrium condensates, using polaritons in semiconductor microcavities. It is a very broad subject since essentially all phenomena discovered and discussed in the context of equilibrium superfluidity are likely to be affected by non-equilibrium. Our aim is to provide a comprehensive theoretical description, and experimental realisation by our project partners, of a broad range of phenomena connected with superfluid behaviour.

Planned Impact

Who will benefit from this research? There are three classes of beneficiaries: 1) general public as recipients of fundamental knowledge about properties of matter (for example science minded pupils, students, people interested in basic knowledge); 2) technological industry (optical/electronic device designers etc...); 3) other academics in mine and related research areas. How will they benefit from this research? 1 class) The proposed project is concerned with a very fundamental problem of a novel type of superfluidity which can exist in highly dissipative and driven light-matter systems. The scientific advances which are likely to take place as a result of this research are substantial. 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 about the quantum states, which inspire imagination of new generation of students and encourage them to take physics degrees. The idea of light-matter particles flowing without resistance in a solid is likely to capture the imagination of young people and attract them to science. Additionally, the project will have a direct educational impact on Warwick Physics 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 real data, comparing theoretical models and their predictions to experimental results). 2 class) It is well known that the conventional electronics will not be keeping up with the Moore's law, and that new technologies need to be considered for progress to continue. If electrons are replaced by photons new regimes of miniaturisation and speed can be reached. Semiconductor microcavities will be particularly suitable for such applications because polaritons in the superfluid regime can travel large distances without dissipation, and decoherence processes are largely reduced. At the same time, due to the very light effective mass of polaritons, such devices could potentially operate at room temperature. 3 class) PDRA and PhD positions, funded by this project, will provide an excellent career development and training opportunities by combining analytical and numerical research with the direct interaction with experiment. Outcomes of the proposed research will also benefit other researchers working in the area of polariton BEC and superfluidity, solid-state condensation and coherence in general, and related phenomena in ultra-cold atomic gases. What will be done to ensure they have the opportunity to benefit from this research? To ensure that these potential beneficiaries can benefit from the project, we will disseminate the results of our investigations widely at international and national conferences, workshops, summer schools, meetings and research visits. Also I will keep my web-page at the University of Warwick updated with the outcomes of our research in the form of uploaded talks, preprints, publications and summaries of current investigations. We expect that the numerical codes, developed within this project, can benefit other researchers: we will be open to either performing requested calculations or providing other scientists with a copy of the codes. We will also undertake some school outreach activities.

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/I028900/1 23/09/2012 29/09/2013 £397,191
EP/I028900/2 Transfer EP/I028900/1 30/09/2013 10/02/2017 £295,981
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