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Jia C, Liang Z. Interaction between an Impurity and Nonlinear Excitations in a Polariton Condensate. ENTROPY (BASEL, SWITZERLAND) 2022; 24:1789. [PMID: 36554194 PMCID: PMC9778002 DOI: 10.3390/e24121789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Exploring the dynamics of a mobile impurity immersed in field excitations is challenging, as it requires to account for the entanglement between the impurity and the surrounding excitations. To this end, the impurity's effective mass has to be considered as finite, rather than infinite. Here, we theoretically investigate the interaction between a finite-mass impurity and a dissipative soliton representing nonlinear excitations in the polariton Bose-Einstein condensate (BEC). Using the Lagrange variational method and the open-dissipative Gross-Pitaevskii equation, we analytically derive the interaction phase diagram between the impurity and a dissipative bright soliton in the polariton BEC. Depending on the impurity mass, we find the dissipative soliton colliding with the impurity can transmit through, get trapped, or be reflected. This work opens a new perspective in understanding the impurity dynamics when immersed in field excitations, as well as potential applications in information processing with polariton solitons.
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Dispersion relation of the collective excitations in a resonantly driven polariton fluid. Nat Commun 2019; 10:3869. [PMID: 31455770 PMCID: PMC6712214 DOI: 10.1038/s41467-019-11886-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/05/2019] [Indexed: 11/18/2022] Open
Abstract
Exciton-polaritons in semiconductor microcavities constitute the archetypal realization of a quantum fluid of light. Under coherent optical drive, remarkable effects such as superfluidity, dark solitons or the nucleation of vortices have been observed, and can be all understood as specific manifestations of the condensate collective excitations. In this work, we perform a Brillouin scattering experiment to measure their dispersion relation \documentclass[12pt]{minimal}
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\begin{document}$$\omega ({\bf{k}})$$\end{document}ω(k) directly. The results, such as a speed of sound which is apparently twice too low, cannot be explained upon considering the polariton condensate alone. In a combined theoretical and experimental analysis, we demonstrate that the presence of an excitonic reservoir alongside the polariton condensate has a dramatic influence on the characteristics of the quantum fluid, and explains our measurement quantitatively. This work clarifies the role of such a reservoir in polariton quantum hydrodynamics. It also provides an unambiguous tool to determine the condensate-to-reservoir fraction in the quantum fluid, and sets an accurate framework to approach ideas for polariton-based quantum-optical applications. Owing to its driven-dissipative nature, and its solid-state environment, a resonantly driven polariton condensate can be accompanied by an incoherent reservoir of excitons. Stepanov et al. demonstrate that this situation strongly modifies the spectrum of collective excitations, which determines many quantum hydrodynamic features in a polariton fluid.
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Juggins RT, Keeling J, Szymańska MH. Coherently driven microcavity-polaritons and the question of superfluidity. Nat Commun 2018; 9:4062. [PMID: 30282978 PMCID: PMC6170389 DOI: 10.1038/s41467-018-06436-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 08/30/2018] [Indexed: 11/09/2022] Open
Abstract
Due to their driven-dissipative nature, photonic quantum fluids present new challenges in understanding superfluidity. Some associated effects have been observed, and notably the report of nearly dissipationless flow for coherently driven microcavity-polaritons was taken as a smoking gun for superflow. Here, we show that the superfluid response—the difference between responses to longitudinal and transverse forces—is zero for coherently driven polaritons. This is a consequence of the gapped excitation spectrum caused by external phase locking. Furthermore, while a normal component exists at finite pump momentum, the remainder forms a rigid state that is unresponsive to either longitudinal or transverse perturbations. Interestingly, the total response almost vanishes when the real part of the excitation spectrum has a linear dispersion, which was the regime investigated experimentally. This suggests that the observed suppression of scattering should be interpreted as a sign of this new rigid state and not a superfluid. Driven-dissipative microcavity polariton experiments find superfluid-like behaviour but the intuition developed from equilibrium systems cannot be straightforwardly applied. Juggins et al. show coherently-driven polaritons are not superfluid and earlier observations instead arise from a distinct rigid state.
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Affiliation(s)
- R T Juggins
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.
| | - J Keeling
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
| | - M H Szymańska
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.
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Relaxation Oscillations and Ultrafast Emission Pulses in a Disordered Expanding Polariton Condensate. Sci Rep 2017; 7:7094. [PMID: 28769102 PMCID: PMC5540918 DOI: 10.1038/s41598-017-07470-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/28/2017] [Indexed: 11/10/2022] Open
Abstract
Semiconductor microcavities are often influenced by structural imperfections, which can disturb the flow and dynamics of exciton-polariton condensates. Additionally, in exciton-polariton condensates there is a variety of dynamical scenarios and instabilities, owing to the properties of the incoherent excitonic reservoir. We investigate the dynamics of an exciton-polariton condensate which emerges in semiconductor microcavity subject to disorder, which determines its spatial and temporal behaviour. Our experimental data revealed complex burst-like time evolution under non-resonant optical pulsed excitation. The temporal patterns of the condensate emission result from the intrinsic disorder and are driven by properties of the excitonic reservoir, which decay in time much slower with respect to the polariton condensate lifetime. This feature entails a relaxation oscillation in polariton condensate formation, resulting in ultrafast emission pulses of coherent polariton field. The experimental data can be well reproduced by numerical simulations, where the condensate is coupled to the excitonic reservoir described by a set of rate equations. Theory suggests the existence of slow reservoir temporarily emptied by stimulated scattering to the condensate, generating ultrashort pulses of the condensate emission.
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Exploring nonlinear topological states of matter with exciton-polaritons: Edge solitons in kagome lattice. Sci Rep 2017; 7:1780. [PMID: 28496151 PMCID: PMC5431788 DOI: 10.1038/s41598-017-01646-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/03/2017] [Indexed: 11/08/2022] Open
Abstract
Matter in nontrivial topological phase possesses unique properties, such as support of unidirectional edge modes on its interface. It is the existence of such modes which is responsible for the wonderful properties of a topological insulator - material which is insulating in the bulk but conducting on its surface, along with many of its recently proposed photonic and polaritonic analogues. We show that exciton-polariton fluid in a nontrivial topological phase in kagome lattice, supports nonlinear excitations in the form of solitons built up from wavepackets of topological edge modes - topological edge solitons. Our theoretical and numerical results indicate the appearance of bright, dark and grey solitons dwelling in the vicinity of the boundary of a lattice strip. In a parabolic region of the dispersion the solitons can be described by envelope functions satisfying the nonlinear Schrödinger equation. Upon collision, multiple topological edge solitons emerge undistorted, which proves them to be true solitons as opposed to solitary waves for which such requirement is waived. Importantly, kagome lattice supports topological edge mode with zero group velocity unlike other types of truncated lattices. This gives a finer control over soliton velocity which can take both positive and negative values depending on the choice of forming it topological edge modes.
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Sun Y, Wen P, Yoon Y, Liu G, Steger M, Pfeiffer LN, West K, Snoke DW, Nelson KA. Bose-Einstein Condensation of Long-Lifetime Polaritons in Thermal Equilibrium. PHYSICAL REVIEW LETTERS 2017; 118:016602. [PMID: 28106443 DOI: 10.1103/physrevlett.118.016602] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Indexed: 06/06/2023]
Abstract
The experimental realization of Bose-Einstein condensation (BEC) with atoms and quasiparticles has triggered wide exploration of macroscopic quantum effects. Microcavity polaritons are of particular interest because quantum phenomena such as BEC and superfluidity can be observed at elevated temperatures. However, polariton lifetimes are typically too short to permit thermal equilibration. This has led to debate about whether polariton condensation is intrinsically a nonequilibrium effect. Here we report the first unambiguous observation of BEC of optically trapped polaritons in thermal equilibrium in a high-Q microcavity, evidenced by equilibrium Bose-Einstein distributions over broad ranges of polariton densities and bath temperatures. With thermal equilibrium established, we verify that polariton condensation is a phase transition with a well-defined density-temperature phase diagram. The measured phase boundary agrees well with the predictions of basic quantum gas theory.
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Affiliation(s)
- Yongbao Sun
- Department of Chemistry and Center for Excitonics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Patrick Wen
- Department of Chemistry and Center for Excitonics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Yoseob Yoon
- Department of Chemistry and Center for Excitonics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Gangqiang Liu
- Department of Physics, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, Pennsylvania 15218, USA
| | - Mark Steger
- Department of Physics, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, Pennsylvania 15218, USA
| | - Loren N Pfeiffer
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Ken West
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - David W Snoke
- Department of Physics, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, Pennsylvania 15218, USA
| | - Keith A Nelson
- Department of Chemistry and Center for Excitonics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Goblot V, Nguyen HS, Carusotto I, Galopin E, Lemaître A, Sagnes I, Amo A, Bloch J. Phase-Controlled Bistability of a Dark Soliton Train in a Polariton Fluid. PHYSICAL REVIEW LETTERS 2016; 117:217401. [PMID: 27911548 DOI: 10.1103/physrevlett.117.217401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Indexed: 06/06/2023]
Abstract
We use a one-dimensional polariton fluid in a semiconductor microcavity to explore the nonlinear dynamics of counterpropagating interacting Bose fluids. The intrinsically driven-dissipative nature of the polariton fluid allows us to use resonant pumping to impose a phase twist across the fluid. When the polariton-polariton interaction energy becomes comparable to the kinetic energy, linear interference fringes transform into a train of solitons. A novel type of bistable behavior controlled by the phase twist across the fluid is experimentally evidenced.
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Affiliation(s)
- V Goblot
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
| | - H S Nguyen
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
| | - I Carusotto
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Italy
| | - E Galopin
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
| | - A Lemaître
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
| | - I Sagnes
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
| | - A Amo
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
| | - J Bloch
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France
- Département de Physique, Ecole Polytechnique, Université Paris Saclay, F-91128 Palaiseau Cedex, France
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Kollath C, Sheikhan A, Wolff S, Brennecke F. Ultracold Fermions in a Cavity-Induced Artificial Magnetic Field. PHYSICAL REVIEW LETTERS 2016; 116:060401. [PMID: 26918972 DOI: 10.1103/physrevlett.116.060401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Indexed: 06/05/2023]
Abstract
We propose how a fermionic quantum gas confined to an optical lattice and coupled to an optical cavity can self-organize into a state where the spontaneously emerging cavity field amplitude induces an artificial magnetic field. The fermions form either a chiral insulator or a chiral liquid carrying chiral currents. The feedback mechanism via the dynamical cavity field enables robust and fast switching in time of the chiral phases, and the cavity output can be employed for a direct nondestructive measurement of the chiral current.
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Affiliation(s)
- Corinna Kollath
- HISKP, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany
| | - Ameneh Sheikhan
- HISKP, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany
| | - Stefan Wolff
- HISKP, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany
| | - Ferdinand Brennecke
- Physikalisches Institut, University of Bonn, Wegelerstr. 8, 53115 Bonn, Germany
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Daskalakis KS, Maier SA, Kéna-Cohen S. Spatial Coherence and Stability in a Disordered Organic Polariton Condensate. PHYSICAL REVIEW LETTERS 2015; 115:035301. [PMID: 26230799 DOI: 10.1103/physrevlett.115.035301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Indexed: 06/04/2023]
Abstract
Although only a handful of organic materials have shown polariton condensation, their study is rapidly becoming more accessible. The spontaneous appearance of long-range spatial coherence is often recognized as a defining feature of such condensates. In this Letter, we study the emergence of spatial coherence in an organic microcavity and demonstrate a number of unique features stemming from the peculiarities of this material set. Despite its disordered nature, we find that correlations extend over the entire spot size, and we measure g(1)(r,r') values of nearly unity at short distances and of 50% for points separated by nearly 10 μm . We show that for large spots, strong shot-to-shot fluctuations emerge as varying phase gradients and defects, including the spontaneous formation of vortices. These are consistent with the presence of modulation instabilities. Furthermore, we find that measurements with flat-top spots are significantly influenced by disorder and can, in some cases, lead to the formation of mutually incoherent localized condensates.
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Affiliation(s)
- K S Daskalakis
- Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| | - S A Maier
- Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| | - S Kéna-Cohen
- Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Québec H3C 3A7, Canada
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