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Orlova A, Blinder R, Kermarrec E, Dupont M, Laflorencie N, Capponi S, Mayaffre H, Berthier C, Paduan-Filho A, Horvatić M. Nuclear Magnetic Resonance Reveals Disordered Level-Crossing Physics in the Bose-Glass Regime of the Br-Doped Ni(Cl_{1-x}Br_{x})_{2}-4SC(NH_{2})_{2} Compound at a High Magnetic Field. PHYSICAL REVIEW LETTERS 2017; 118:067203. [PMID: 28234518 DOI: 10.1103/physrevlett.118.067203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Indexed: 06/06/2023]
Abstract
By measuring the nuclear magnetic resonance (NMR) T_{1}^{-1} relaxation rate in the Br (bond) doped DTN compound, Ni(Cl_{1-x}Br_{x})_{2}-4SC(NH_{2})_{2}(DTNX), we show that the low-energy spin dynamics of its high magnetic field "Bose-glass" regime is dominated by a strong peak of spin fluctuations found at the nearly doping-independent position H^{*}≅13.6 T. From its temperature and field dependence, we conclude that this corresponds to a level crossing of the energy levels related to the doping-induced impurity states. Observation of the local NMR signal from the spin adjacent to the doped Br allowed us to fully characterize this impurity state. We have thus quantified a microscopic theoretical model that paves the way to better understanding of the Bose-glass physics in DTNX, as revealed in the related theoretical study [M. Dupont, S. Capponi, and N. Laflorencie, Phys. Rev. Lett. 118, 067204 (2017).PRLTAO0031-900710.1103/PhysRevLett.118.067204].
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Affiliation(s)
- Anna Orlova
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, UGA, UPS, and INSA, Boîte Postale 166, 38042, Grenoble Cedex 9, France
| | - Rémi Blinder
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, UGA, UPS, and INSA, Boîte Postale 166, 38042, Grenoble Cedex 9, France
| | - Edwin Kermarrec
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, UGA, UPS, and INSA, Boîte Postale 166, 38042, Grenoble Cedex 9, France
| | - Maxime Dupont
- Laboratoire de Physique Théorique, IRSAMC, Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Nicolas Laflorencie
- Laboratoire de Physique Théorique, IRSAMC, Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Sylvain Capponi
- Laboratoire de Physique Théorique, IRSAMC, Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Hadrien Mayaffre
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, UGA, UPS, and INSA, Boîte Postale 166, 38042, Grenoble Cedex 9, France
| | - Claude Berthier
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, UGA, UPS, and INSA, Boîte Postale 166, 38042, Grenoble Cedex 9, France
| | | | - Mladen Horvatić
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS (UPR3228), EMFL, UGA, UPS, and INSA, Boîte Postale 166, 38042, Grenoble Cedex 9, France
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Efimkin DK, Galitski V. Anomalous Coulomb Drag in Electron-Hole Bilayers due to the Formation of Excitons. PHYSICAL REVIEW LETTERS 2016; 116:046801. [PMID: 26871349 DOI: 10.1103/physrevlett.116.046801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Indexed: 06/05/2023]
Abstract
Several recent experiments have reported an anomalous temperature dependence of the Coulomb drag effect in electron-hole bilayers. Motivated by these puzzling data, we study theoretically a low-density electron-hole bilayer, where electrons and holes avoid quantum degeneracy by forming excitons. We describe the ionization-recombination crossover between the electron-hole plasma and exciton gas and calculate both the intralayer and drag resistivity as a function of temperature. The latter exhibits a minimum followed by a sharp upturn at low temperatures, in qualitative agreement with the experimental observations [see, e.g., J. A. Seamons et al., Phys. Rev. Lett. 102, 026804 (2009)]. Importantly, the drag resistivity in the proposed scenario is found to be rather insensitive to a mismatch in electron and hole concentrations, in sharp contrast to the scenario of electron-hole Cooper pairing.
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Affiliation(s)
- Dmitry K Efimkin
- Joint Quantum Institute and Condensed Matter Theory Center, University of Maryland, College Park, Maryland 20742-4111, USA
| | - Victor Galitski
- Joint Quantum Institute and Condensed Matter Theory Center, University of Maryland, College Park, Maryland 20742-4111, USA
- School of Physics, Monash University, Melbourne, Victoria 3800, Australia
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3
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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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Plumhof JD, Stöferle T, Mai L, Scherf U, Mahrt RF. Room-temperature Bose-Einstein condensation of cavity exciton-polaritons in a polymer. NATURE MATERIALS 2014; 13:247-52. [PMID: 24317189 DOI: 10.1038/nmat3825] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/29/2013] [Indexed: 05/02/2023]
Abstract
A Bose-Einstein condensate (BEC) is a state of matter in which extensive collective coherence leads to intriguing macroscopic quantum phenomena. In crystalline semiconductor microcavities, bosonic quasiparticles, known as exciton-polaritons, can be created through strong coupling between bound electron-hole pairs and the photon field. Recently, a non-equilibrium BEC (ref. ) and superfluidity have been demonstrated in such structures. With organic crystals grown inside dielectric microcavities, signatures of polariton lasing have been observed. However, owing to the deleterious effects of disorder and material imperfection on the condensed phase, only crystalline materials of the highest quality have been used until now. Here we demonstrate non-equilibrium BEC of exciton-polaritons in a polymer-filled microcavity at room temperature. We observe thermalization of polaritons and, above a critical excitation density, clear evidence of condensation at zero in-plane momentum, namely nonlinear behaviour, blueshifted emission and long-range coherence. The key signatures distinguishing the behaviour from conventional photon lasing are presented. As no crystal growth is involved, our approach radically reduces the complexity of experiments to investigate BEC physics and paves the way for a new generation of opto-electronic devices, taking advantage of the processability and flexibility of polymers.
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Affiliation(s)
- Johannes D Plumhof
- 1] IBM Research-Zurich, Säumerstrasse 4, Rüschlikon 8803, Switzerland [2]
| | - Thilo Stöferle
- IBM Research-Zurich, Säumerstrasse 4, Rüschlikon 8803, Switzerland
| | - Lijian Mai
- IBM Research-Zurich, Säumerstrasse 4, Rüschlikon 8803, Switzerland
| | - Ullrich Scherf
- Macromolecular Chemistry Group and Institute for Polymer Technology, Bergische Universität Wuppertal, Gauss-Strasse 20, 42119 Wuppertal, Germany
| | - Rainer F Mahrt
- IBM Research-Zurich, Säumerstrasse 4, Rüschlikon 8803, Switzerland
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Janot A, Hyart T, Eastham PR, Rosenow B. Superfluid stiffness of a driven dissipative condensate with disorder. PHYSICAL REVIEW LETTERS 2013; 111:230403. [PMID: 24476236 DOI: 10.1103/physrevlett.111.230403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/25/2013] [Indexed: 06/03/2023]
Abstract
Observations of macroscopic quantum coherence in driven systems, e.g. polariton condensates, have strongly stimulated experimental as well as theoretical efforts during the last decade. We address the question of whether a driven quantum condensate is a superfluid, allowing for the effects of disorder and its nonequilibrium nature. We predict that for spatial dimensions d<4 the superfluid stiffness vanishes once the condensate exceeds a critical size, and treat in detail the case d=2. Thus a nonequilibrium condensate is not a superfluid in the thermodynamic limit, even for weak disorder, although superfluid behavior would persist in small systems.
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Affiliation(s)
- Alexander Janot
- Institut für Theoretische Physik, Universität Leipzig, 04009 Leipzig, Germany
| | - Timo Hyart
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, Netherlands
| | - Paul R Eastham
- School of Physics and CRANN, Trinity College, Dublin 2, Ireland
| | - Bernd Rosenow
- Institut für Theoretische Physik, Universität Leipzig, 04009 Leipzig, Germany
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Manni F, Lagoudakis KG, Pietka B, Fontanesi L, Wouters M, Savona V, André R, Deveaud-Plédran B. Polariton condensation in a one-dimensional disordered potential. PHYSICAL REVIEW LETTERS 2011; 106:176401. [PMID: 21635053 DOI: 10.1103/physrevlett.106.176401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 03/24/2011] [Indexed: 05/30/2023]
Abstract
We study the coherence and density modulation of a nonequilibrium exciton-polariton condensate in a one-dimensional valley with disorder. By means of interferometric measurements we evidence a modulation of the first-order coherence function and we relate it to a disorder-induced modulation of the condensate density, that increases as the pump power is increased. The nonmonotonic spatial coherence function is found to be the result of the strong nonequilibrium character of the one-dimensional system, in the presence of disorder.
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Affiliation(s)
- F Manni
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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Shelykh IA, Taylor T, Kavokin AV. Rotons in a hybrid Bose-Fermi system. PHYSICAL REVIEW LETTERS 2010; 105:140402. [PMID: 21230816 DOI: 10.1103/physrevlett.105.140402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 08/10/2010] [Indexed: 05/30/2023]
Abstract
We calculate the spectrum of elementary excitations in a two-dimensional exciton condensate in the vicinity of a two-dimensional electron gas. We show that attraction of excitons due to their scattering with free electrons may lead to formation of a roton minimum. The energy of this minimum may go below the ground state energy which manifests breaking of the superfluidity. The Berezinsky-Kosterlitz-Thouless phase transition temperature decreases due to the exciton-exciton attraction mediated by electrons.
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Affiliation(s)
- Ivan A Shelykh
- Science Institute, University of Iceland, Dunhagi-3, IS-107, Reykjavik, Iceland
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8
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Collective fluid dynamics of a polariton condensate in a semiconductor microcavity. Nature 2009; 457:291-5. [DOI: 10.1038/nature07640] [Citation(s) in RCA: 455] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Accepted: 11/13/2008] [Indexed: 11/08/2022]
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9
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Liew TCH, Rubo YG, Kavokin AV. Generation and dynamics of vortex lattices in coherent exciton-polariton fields. PHYSICAL REVIEW LETTERS 2008; 101:187401. [PMID: 18999864 DOI: 10.1103/physrevlett.101.187401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Indexed: 05/27/2023]
Abstract
Vortex dynamics in coherent ensembles of exciton polaritons (condensates) is studied in the framework of the polarization-dependent Gross-Pitaevskii equation. Vortex lattices can be resonantly excited in the polariton field by the interference of three or more optical pumps. Vortex-antivortex pairs can also appear in polariton condensates due to scattering with disorder. The nonlinear vortex dynamics is characterized by interactions of vortex cores and vortex-antivortex recombination.
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Affiliation(s)
- T C H Liew
- School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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Kasprzak J, Solnyshkov DD, André R, Dang LS, Malpuech G. Formation of an exciton polariton condensate: thermodynamic versus kinetic regimes. PHYSICAL REVIEW LETTERS 2008; 101:146404. [PMID: 18851551 DOI: 10.1103/physrevlett.101.146404] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 08/11/2008] [Indexed: 05/26/2023]
Abstract
We measure the polariton distribution function and the condensation threshold versus the photon-exciton detuning and the lattice temperature in a CdTe microcavity under nonresonant pumping. The results are reproduced by simulations using semiclassical Boltzmann equations. At negative detuning we find a kinetic condensation regime: the distribution is not thermal and the threshold is governed by the relaxation kinetics. At positive detuning, the distribution becomes thermal and the threshold is governed by the thermodynamic parameters of the system. Both regimes are a manifestation of polariton lasing, whereas only the latter is related to Bose-Einstein condensation defined as an equilibrium phase transition.
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Affiliation(s)
- J Kasprzak
- CEA-CNRS Group "Nanophysique et Semiconducteurs," Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9, France
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11
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Liew TCH, Kavokin AV, Shelykh IA. Optical circuits based on polariton neurons in semiconductor microcavities. PHYSICAL REVIEW LETTERS 2008; 101:016402. [PMID: 18764129 DOI: 10.1103/physrevlett.101.016402] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 05/06/2008] [Indexed: 05/26/2023]
Abstract
By exploiting the polarization multistability of polaritons, we show that polarized signals can be conducted in the plane of a semiconductor microcavity along controlled channels or "neurons." Furthermore, because of the interaction of polaritons with opposite spins it is possible to realize binary logic gates operating on the polarization degree of freedom. Multiple gates can be integrated together to form an optical circuit contained in a single semiconductor microcavity.
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Affiliation(s)
- T C H Liew
- School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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12
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Baas A, Lagoudakis KG, Richard M, André R, Dang LS, Deveaud-Plédran B. Synchronized and desynchronized phases of exciton-polariton condensates in the presence of disorder. PHYSICAL REVIEW LETTERS 2008; 100:170401. [PMID: 18518258 DOI: 10.1103/physrevlett.100.170401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 05/01/2007] [Indexed: 05/26/2023]
Abstract
Condensation of exciton polaritons in semiconductor microcavities takes place despite in-plane disorder. Below the critical density, the inhomogeneity of the disorder limits the spatial extension of the ground state. Above the critical density, in the presence of weak disorder, this limitation is spontaneously overcome by the nonlinear interaction, resulting in an extended synchronized phase. In the case of strong disorder, several non-phase-locked condensates can be evidenced. The transition from a synchronized phase to a desynchronized phase is addressed by sampling the cavity disorder.
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Affiliation(s)
- A Baas
- IPEQ, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
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