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Shan H, Drawer JC, Sun M, Anton-Solanas C, Esmann M, Yumigeta K, Watanabe K, Taniguchi T, Tongay S, Höfling S, Savenko I, Schneider C. Second-Order Temporal Coherence of Polariton Lasers Based on an Atomically Thin Crystal in a Microcavity. PHYSICAL REVIEW LETTERS 2023; 131:206901. [PMID: 38039456 DOI: 10.1103/physrevlett.131.206901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/28/2023] [Accepted: 10/06/2023] [Indexed: 12/03/2023]
Abstract
Bosonic condensation and lasing of exciton polaritons in microcavities is a fascinating solid-state phenomenon. It provides a versatile platform to study out-of-equilibrium many-body physics and has recently appeared at the forefront of quantum technologies. Here, we study the photon statistics via the second-order temporal correlation function of polariton lasing emerging from an optical microcavity with an embedded atomically thin MoSe_{2} crystal. Furthermore, we investigate the macroscopic polariton phase transition for varying excitation powers and temperatures. The lower-polariton exhibits photon bunching below the threshold, implying a dominant thermal distribution of the emission, while above the threshold, the second-order correlation transits towards unity, which evidences the formation of a coherent state. Our findings are in agreement with a microscopic numerical model, which explicitly includes scattering with phonons on the quantum level.
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Affiliation(s)
- Hangyong Shan
- Institute of Physics, Carl von Ossietzky University, 26129 Oldenburg, Germany
| | | | - Meng Sun
- Faculty of Science, Beijing University of Technology, 100124 Beijing, China
| | - Carlos Anton-Solanas
- Departamento de Física de Materiales, Instituto Nicolás Cabrera, Instituto de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Martin Esmann
- Institute of Physics, Carl von Ossietzky University, 26129 Oldenburg, Germany
| | - Kentaro Yumigeta
- School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287, USA
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Sefaattin Tongay
- School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287, USA
| | - Sven Höfling
- Julius-Maximilians-Universität Würzburg, Physikalisches Institut and Würzburg-Dresden Cluster of Excellence ct.qmat, Lehrstuhl für Technische Physik, Am Hubland, 97074 Würzburg, Germany
| | - Ivan Savenko
- Guangdong Technion Israel Institute of Technology (GTIIT), 241 Daxue Road, Shantou, Guangdong Province 515603, China
- Technion-Israel Institute of Technology, 32000 Haifa, Israel
- Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion, Guangdong Technion-Israel Institute of Technology, Guangdong 515063, China
| | - Christian Schneider
- Institute of Physics, Carl von Ossietzky University, 26129 Oldenburg, Germany
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Room-temperature electrical control of polarization and emission angle in a cavity-integrated 2D pulsed LED. Nat Commun 2022; 13:4884. [PMID: 35985999 PMCID: PMC9391484 DOI: 10.1038/s41467-022-32292-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 07/25/2022] [Indexed: 11/08/2022] Open
Abstract
Devices based on two-dimensional (2D) semiconductors hold promise for the realization of compact and versatile on-chip interconnects between electrical and optical signals. Although light emitting diodes (LEDs) are fundamental building blocks for integrated photonics, the fabrication of light sources made of bulk materials on complementary metal-oxide-semiconductor (CMOS) circuits is challenging. While LEDs based on van der Waals heterostructures have been realized, the control of the emission properties necessary for information processing remains limited. Here, we show room-temperature electrical control of the location, directionality and polarization of light emitted from a 2D LED operating at MHz frequencies. We integrate the LED in a planar cavity to couple the polariton emission angle and polarization to the in-plane exciton momentum, controlled by a lateral voltage. These findings demonstrate the potential of TMDCs as fast, compact and tunable light sources, promising for the realization of electrically driven polariton lasers. 2D semiconductors offer a promising platform for the realization of compact and CMOS-compatible optoelectronic components. Here, the authors report the realization of light-emitting diodes based on 2D WSe2 integrated with a planar cavity, showing the electrical control of the emission angle and polarization at room temperature.
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3
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Anton-Solanas C, Waldherr M, Klaas M, Suchomel H, Harder TH, Cai H, Sedov E, Klembt S, Kavokin AV, Tongay S, Watanabe K, Taniguchi T, Höfling S, Schneider C. Bosonic condensation of exciton-polaritons in an atomically thin crystal. NATURE MATERIALS 2021; 20:1233-1239. [PMID: 33958772 DOI: 10.1038/s41563-021-01000-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
The emergence of two-dimensional crystals has revolutionized modern solid-state physics. From a fundamental point of view, the enhancement of charge carrier correlations has sparked much research activity in the transport and quantum optics communities. One of the most intriguing effects, in this regard, is the bosonic condensation and spontaneous coherence of many-particle complexes. Here we find compelling evidence of bosonic condensation of exciton-polaritons emerging from an atomically thin crystal of MoSe2 embedded in a dielectric microcavity under optical pumping at cryogenic temperatures. The formation of the condensate manifests itself in a sudden increase of luminescence intensity in a threshold-like manner, and a notable spin-polarizability in an externally applied magnetic field. Spatial coherence is mapped out via highly resolved real-space interferometry, revealing a spatially extended condensate. Our device represents a decisive step towards the implementation of coherent light-sources based on atomically thin crystals, as well as non-linear, valleytronic coherent devices.
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Affiliation(s)
- Carlos Anton-Solanas
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany.
- Institute of Physics, Carl von Ossietzky University, Oldenburg, Germany.
| | - Maximilian Waldherr
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - Martin Klaas
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - Holger Suchomel
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - Tristan H Harder
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - Hui Cai
- University of California, Merced, Merced, CA, USA
| | - Evgeny Sedov
- School of Science, Westlake University, Hangzhou, P. R. China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, P. R. China
- Vladimir State University named after A.G. and N.G. Stoletovs, Vladimir, Russia
| | - Sebastian Klembt
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - Alexey V Kavokin
- School of Science, Westlake University, Hangzhou, P. R. China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, P. R. China
- Spin Optics Laboratory, St Petersburg State University, St Petersburg, Russia
| | - Sefaattin Tongay
- School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA.
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Sven Höfling
- Technische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
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4
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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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5
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Kwon MS, Oh BY, Gong SH, Kim JH, Kang HK, Kang S, Song JD, Choi H, Cho YH. Direct Transfer of Light's Orbital Angular Momentum onto a Nonresonantly Excited Polariton Superfluid. PHYSICAL REVIEW LETTERS 2019; 122:045302. [PMID: 30768308 DOI: 10.1103/physrevlett.122.045302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/29/2018] [Indexed: 06/09/2023]
Abstract
Recently, exciton polaritons in a semiconductor microcavity were found to condense into a coherent ground state much like a Bose-Einstein condensate and a superfluid. They have become a unique testbed for generating and manipulating quantum vortices in a driven-dissipative superfluid. Here, we generate an exciton-polariton condensate with a nonresonant Laguerre-Gaussian optical beam and verify the direct transfer of light's orbital angular momentum to an exciton-polariton quantum fluid. Quantized vortices are found in spite of the large energy relaxation involved in nonresonant pumping. We identified phase singularity, density distribution, and energy eigenstates for the vortex states. Our observations confirm that nonresonant optical Laguerre-Gaussian beam can be used to manipulate chirality, topological charge, and stability of the nonequilibrium quantum fluid. These vortices are quite robust, only sensitive to the orbital angular momentum of light and not other parameters such as energy, intensity, size, or shape of the pump beam. Therefore, optical information can be transferred between the photon and exciton-polariton with ease and the technique is potentially useful to form the controllable network of multiple topological charges even in the presence of spectral randomness in a solid state system.
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Affiliation(s)
- Min-Sik Kwon
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Byoung Yong Oh
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Su-Hyun Gong
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Department of Physics, Korea University, 45 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Je-Hyung Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hang Kyu Kang
- Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Sooseok Kang
- Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jin Dong Song
- Center for Opto-Electronic Convergence Systems, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Hyoungsoon Choi
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yong-Hoon Cho
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
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6
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Wang J, Su R, Xing J, Bao D, Diederichs C, Liu S, Liew TCH, Chen Z, Xiong Q. Room Temperature Coherently Coupled Exciton-Polaritons in Two-Dimensional Organic-Inorganic Perovskite. ACS NANO 2018; 12:8382-8389. [PMID: 30089200 DOI: 10.1021/acsnano.8b03737] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Two-dimensional (2D) organic-inorganic perovskite semiconductors with natural multiquantum well structures and confined 2D excitons are intriguing for the study of strong exciton-photon coupling, due to their large exciton binding energy and oscillation strength. This strong coupling leads to a formation of the half-light half-matter bosonic quasiparticle called exciton-polariton, consisting of a linear superposition state between photonic and excitonic states. Here, we demonstrate room temperature strong coupling in exfoliated wavelength-tunable 2D organic-inorganic perovskite semiconductors embedded into a planar microcavity, exhibiting large energetic splitting-to-line width ratios (>34.2). Angular-dependent spectroscopy measurements reveal that hybridized polariton states act as an ultrafast and reversible energy oscillation, involving 2D perovskite exciton, cavity modes (CM), and Bragg modes of the distributed Bragg reflector. Meanwhile, sizable hybrid particles dominantly couple to the measured optical field through the CMs. Our findings advocate a considerable promise of 2D organic-inorganic perovskite to explore fundamental quantum phenomena such as Bose-Einstein condensation, superfluidity, and exciton-polariton networks.
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Affiliation(s)
- Jun Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Collaborative Innovation Center of Advanced Microstructures , Fudan University , Shanghai 200433 , P.R. China
| | - Rui Su
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
| | - Jun Xing
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
| | - Di Bao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
| | - Carole Diederichs
- MajuLab, CNRS-UCA-SU-NUS-NTU International Joint Research Unit, UMI 3654, Singapore 639798
- Laboratoire Pierre Aigrain, Département de physique de l'ENS, Ecole normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité , Sorbonne Universités, UPMC Univ. Paris 06, CNRS , Paris 75005 , France
| | - Sheng Liu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
| | - Timothy C H Liew
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
| | - Zhanghai Chen
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Collaborative Innovation Center of Advanced Microstructures , Fudan University , Shanghai 200433 , P.R. China
| | - Qihua Xiong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371
- MajuLab, CNRS-UCA-SU-NUS-NTU International Joint Research Unit, UMI 3654, Singapore 639798
- NOVITAS, Nanoelectronics Center of Excellence, School of Electrical and Electronic Engineering , Nanyang Technological University , Singapore 639798
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7
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Observation of bosonic condensation in a hybrid monolayer MoSe 2-GaAs microcavity. Nat Commun 2018; 9:3286. [PMID: 30115908 PMCID: PMC6095855 DOI: 10.1038/s41467-018-05532-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/11/2018] [Indexed: 11/09/2022] Open
Abstract
Bosonic condensation belongs to the most intriguing phenomena in physics, and was mostly reserved for experiments with ultra-cold quantum gases. More recently, it became accessible in exciton-based solid-state systems at elevated temperatures. Here, we demonstrate bosonic condensation driven by excitons hosted in an atomically thin layer of MoSe2, strongly coupled to light in a solid-state resonator. The structure is operated in the regime of collective strong coupling between a Tamm-plasmon resonance, GaAs quantum well excitons, and two-dimensional excitons confined in the monolayer crystal. Polariton condensation in a monolayer crystal manifests by a superlinear increase of emission intensity from the hybrid polariton mode, its density-dependent blueshift, and a dramatic collapse of the emission linewidth, a hallmark of temporal coherence. Importantly, we observe a significant spin-polarization in the injected polariton condensate, a fingerprint for spin-valley locking in monolayer excitons. Our results pave the way towards highly nonlinear, coherent valleytronic devices and light sources. Atomically thin transition metal dichalcogenides are an ideal platform to investigate the underlying physics of strongly bound excitons in low dimensions. Here, the authors demonstrate the formation of a bosonic condensate driven by excitons in two-dimensional MoSe2 strongly coupled to light in a solid-state resonator.
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8
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Single-shot condensation of exciton polaritons and the hole burning effect. Nat Commun 2018; 9:2944. [PMID: 30093641 PMCID: PMC6085311 DOI: 10.1038/s41467-018-05349-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/27/2018] [Indexed: 11/08/2022] Open
Abstract
A bosonic condensate of exciton polaritons in a semiconductor microcavity is a macroscopic quantum state subject to pumping and decay. The fundamental nature of this driven-dissipative condensate is still under debate. Here, we gain an insight into spontaneous condensation by imaging long-lifetime exciton polaritons in a high-quality inorganic microcavity in a single-shot optical excitation regime, without averaging over multiple condensate realisations. We demonstrate that condensation is strongly influenced by an incoherent reservoir and that the reservoir depletion, the so-called spatial hole burning, is critical for the transition to the ground state. Condensates of photon-like polaritons exhibit strong shot-to-shot fluctuations and density filamentation due to the effective self-focusing associated with the reservoir depletion. In contrast, condensates of exciton-like polaritons display smoother spatial density distributions and are second-order coherent. Our observations show that the single-shot measurements offer a unique opportunity to study fundamental properties of non-equilibrium condensation in the presence of a reservoir.
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9
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Caputo D, Ballarini D, Dagvadorj G, Sánchez Muñoz C, De Giorgi M, Dominici L, West K, Pfeiffer LN, Gigli G, Laussy FP, Szymańska MH, Sanvitto D. Topological order and thermal equilibrium in polariton condensates. NATURE MATERIALS 2018; 17:145-151. [PMID: 29200196 DOI: 10.1038/nmat5039] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
The Berezinskii-Kosterlitz-Thouless phase transition from a disordered to a quasi-ordered state, mediated by the proliferation of topological defects in two dimensions, governs seemingly remote physical systems ranging from liquid helium, ultracold atoms and superconducting thin films to ensembles of spins. Here we observe such a transition in a short-lived gas of exciton-polaritons, bosonic light-matter particles in semiconductor microcavities. The observed quasi-ordered phase, characteristic for an equilibrium two-dimensional bosonic gas, with a decay of coherence in both spatial and temporal domains with the same algebraic exponent, is reproduced with numerical solutions of stochastic dynamics, proving that the mechanism of pairing of the topological defects (vortices) is responsible for the transition to the algebraic order. This is made possible thanks to long polariton lifetimes in high-quality samples and in a reservoir-free region. Our results show that the joint measurement of coherence both in space and time is required to characterize driven-dissipative phase transitions and enable the investigation of topological ordering in open systems.
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Affiliation(s)
- Davide Caputo
- CNR NANOTEC-Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy
- University of Salento, Via Arnesano, 73100 Lecce, Italy
| | - Dario Ballarini
- CNR NANOTEC-Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy
| | - Galbadrakh Dagvadorj
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
| | | | - Milena De Giorgi
- CNR NANOTEC-Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy
| | - Lorenzo Dominici
- CNR NANOTEC-Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy
| | - Kenneth West
- PRISM, Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08540, USA
| | - Loren N Pfeiffer
- PRISM, Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08540, USA
| | - Giuseppe Gigli
- CNR NANOTEC-Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy
- University of Salento, Via Arnesano, 73100 Lecce, Italy
| | - Fabrice P Laussy
- Faculty of Science and Engineering, University of Wolverhampton, Wulfruna Street, WV1 1LY, UK
- Russian Quantum Center, Novaya 100, 143025 Skolkovo, Moscow Region, Russia
| | - Marzena H Szymańska
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| | - Daniele Sanvitto
- CNR NANOTEC-Institute of Nanotechnology, Via Monteroni, 73100 Lecce, Italy
- INFN sezione di Lecce, 73100 Lecce, Italy
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10
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Klembt S, Stepanov P, Klein T, Minguzzi A, Richard M. Thermal Decoherence of a Nonequilibrium Polariton Fluid. PHYSICAL REVIEW LETTERS 2018; 120:035301. [PMID: 29400531 DOI: 10.1103/physrevlett.120.035301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 11/02/2017] [Indexed: 06/07/2023]
Abstract
Exciton polaritons constitute a unique realization of a quantum fluid interacting with its environment. Using selenide-based microcavities, we exploit this feature to warm up a polariton condensate in a controlled way and monitor its spatial coherence. We determine directly the amount of heat picked up by the condensate by measuring the phonon-polariton scattering rate and comparing it with the loss rate. We find that, upon increasing the heating rate, the spatial coherence length decreases markedly, while localized phase structures vanish, in good agreement with a stochastic mean-field theory. From the thermodynamical point of view, this regime is unique, as it involves a nonequilibrium quantum fluid with no well-defined temperature but which is nevertheless able to pick up heat with dramatic effects on the order parameter.
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Affiliation(s)
- Sebastian Klembt
- Université Grenoble Alpes, CNRS, Institut Néel, 38000 Grenoble, France
| | - Petr Stepanov
- Université Grenoble Alpes, CNRS, Institut Néel, 38000 Grenoble, France
| | - Thorsten Klein
- University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
| | - Anna Minguzzi
- Université Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
| | - Maxime Richard
- Université Grenoble Alpes, CNRS, Institut Néel, 38000 Grenoble, France
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11
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Rojan K, Léger Y, Morigi G, Richard M, Minguzzi A. Enhanced Second-Order Nonlinearity for THz Generation by Resonant Interaction of Exciton-Polariton Rabi Oscillations with Optical Phonons. PHYSICAL REVIEW LETTERS 2017; 119:127401. [PMID: 29341639 DOI: 10.1103/physrevlett.119.127401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Indexed: 06/07/2023]
Abstract
Semiconductor microcavities in the strong-coupling regime exhibit an energy scale in the terahertz (THz) frequency range, which is fixed by the Rabi splitting between the upper and lower exciton-polariton states. While this range can be tuned by several orders of magnitude using different excitonic media, the transition between both polaritonic states is dipole forbidden. In this work, we show that, in cadmium telluride microcavities, the Rabi-oscillation-driven THz radiation is actually active without the need for any change in the microcavity design. This feature results from the unique resonance condition which is achieved between the Rabi splitting and the phonon-polariton states and leads to a giant enhancement of the second-order nonlinearity.
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Affiliation(s)
- Katharina Rojan
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
- Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany
| | - Yoan Léger
- UMR FOTON, CNRS, INSA, F-35708 Rennes, France
| | - Giovanna Morigi
- Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany
| | - Maxime Richard
- Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Univ. Grenoble Alpes), Institut Néel, 38000 Grenoble, France
| | - Anna Minguzzi
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
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12
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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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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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Zaster S, Bittner ER, Piryatinski A. Quantum Symmetry Breaking of Exciton/Polaritons in a Metal-Nanorod Plasmonic Array. J Phys Chem A 2016; 120:3109-16. [DOI: 10.1021/acs.jpca.5b10726] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Svitlana Zaster
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Eric R. Bittner
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Andrei Piryatinski
- Theoretical
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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15
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Bhattacharya P, Frost T, Deshpande S, Baten MZ, Hazari A, Das A. Room temperature electrically injected polariton laser. PHYSICAL REVIEW LETTERS 2014; 112:236802. [PMID: 24972222 DOI: 10.1103/physrevlett.112.236802] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Indexed: 05/02/2023]
Abstract
Room temperature electrically pumped inversionless polariton lasing is observed from a bulk GaN-based microcavity diode. The low nonlinear threshold for polariton lasing occurs at 169 A/cm(2) in the light-current characteristics, accompanied by a collapse of the emission linewidth and small blueshift of the emission peak. Measurement of angle-resolved luminescence, polariton condensation and occupation in momentum space, and output spatial coherence and polarization have also been made. A second threshold, due to conventional photon lasing, is observed at an injection of 44 kA/cm(2).
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Affiliation(s)
- Pallab Bhattacharya
- Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA
| | - Thomas Frost
- Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA
| | - Saniya Deshpande
- Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA
| | - Md Zunaid Baten
- Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA
| | - Arnab Hazari
- Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA
| | - Ayan Das
- Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA
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Shi L, Hakala TK, Rekola HT, Martikainen JP, Moerland RJ, Törmä P. Spatial coherence properties of organic molecules coupled to plasmonic surface lattice resonances in the weak and strong coupling regimes. PHYSICAL REVIEW LETTERS 2014; 112:153002. [PMID: 24785036 DOI: 10.1103/physrevlett.112.153002] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Indexed: 05/26/2023]
Abstract
We study spatial coherence properties of a system composed of periodic silver nanoparticle arrays covered with a fluorescent organic molecule (DiD) film. The evolution of spatial coherence of this composite structure from the weak to the strong coupling regime is investigated by systematically varying the coupling strength between the localized DiD excitons and the collective, delocalized modes of the nanoparticle array known as surface lattice resonances. A gradual evolution of coherence from the weak to the strong coupling regime is observed, with the strong coupling features clearly visible in interference fringes. A high degree of spatial coherence is demonstrated in the strong coupling regime, even when the mode is very excitonlike (80%), in contrast to the purely localized nature of molecular excitons. We show that coherence appears in proportion to the weight of the plasmonic component of the mode throughout the weak-to-strong coupling crossover, providing evidence for the hybrid nature of the normal modes.
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Affiliation(s)
- L Shi
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
| | - T K Hakala
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
| | - H T Rekola
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
| | - J-P Martikainen
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
| | - R J Moerland
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland and Department of Imaging Physics, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, NL-2628 CJ, Delft, The Netherlands
| | - P Törmä
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
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17
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Aßmann M, Tempel JS, Veit F, Bayer M, Rahimi-Iman A, Löffler A, Höfling S, Reitzenstein S, Worschech L, Forchel A. From polariton condensates to highly photonic quantum degenerate states of bosonic matter. Proc Natl Acad Sci U S A 2011; 108:1804-9. [PMID: 21245353 PMCID: PMC3033249 DOI: 10.1073/pnas.1009847108] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bose-Einstein condensation (BEC) is a thermodynamic phase transition of an interacting Bose gas. Its key signatures are remarkable quantum effects like superfluidity and a phonon-like Bogoliubov excitation spectrum, which have been verified for atomic BECs. In the solid state, BEC of exciton-polaritons has been reported. Polaritons are strongly coupled light-matter quasiparticles in semiconductor microcavities and composite bosons. However, they are subject to dephasing and decay and need external pumping to reach a steady state. Accordingly the polariton BEC is a nonequilibrium process of a degenerate polariton gas in self-equilibrium, but out of equilibrium with the baths it is coupled to and therefore deviates from the thermodynamic phase transition seen in atomic BECs. Here we show that key signatures of BEC can even be observed without fulfilling the self-equilibrium condition in a highly photonic quantum degenerate nonequilibrium system.
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Affiliation(s)
- Marc Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany; and
| | - Jean-Sebastian Tempel
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany; and
| | - Franziska Veit
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany; and
| | - Manfred Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany; and
| | - Arash Rahimi-Iman
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Germany
| | - Andreas Löffler
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Germany
| | - Sven Höfling
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Germany
| | - Stephan Reitzenstein
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Germany
| | - Lukas Worschech
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Germany
| | - Alfred Forchel
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Germany
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18
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López-García M, Galisteo-López JF, Blanco A, Sánchez-Marcos J, López C, García-Martín A. Enhancement and directionality of spontaneous emission in hybrid self-assembled photonic-plasmonic crystals. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:1757-1761. [PMID: 20665752 DOI: 10.1002/smll.201000216] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Martín López-García
- Instituto de Ciencia de Materiales de Madrid (CSIC) and Unidad Asociada CSIC-U. Vigo C/Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain
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19
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Wouters M, Carusotto I. Superfluidity and critical velocities in nonequilibrium Bose-Einstein condensates. PHYSICAL REVIEW LETTERS 2010; 105:020602. [PMID: 20867695 DOI: 10.1103/physrevlett.105.020602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/11/2010] [Indexed: 05/29/2023]
Abstract
We theoretically study the superfluidity properties of a nonequilibrium Bose-Einstein condensate of exciton polaritons in a semiconductor microcavity under incoherent pumping. The dynamics of the condensate is described at mean-field level in terms of a generalized Gross-Pitaevskii equation. The drag force on a small moving object and the onset of fringes in the density profile are shown to have a sharp threshold as a function of the velocity; a generalized Landau criterion is developed to explain this behavior in terms of the dispersion of elementary excitations. Metastability of supercurrents in multiply-connected geometries is shown to persist up to higher flow speeds.
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Affiliation(s)
- Michiel Wouters
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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20
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Kasprzak J, Richard M, Baas A, Deveaud B, André R, Poizat JP, Dang LS. Second-order time correlations within a polariton Bose-Einstein condensate in a CdTe microcavity. PHYSICAL REVIEW LETTERS 2008; 100:067402. [PMID: 18352514 DOI: 10.1103/physrevlett.100.067402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Indexed: 05/04/2023]
Abstract
Second-order time correlations of polaritons have been measured across the condensation threshold in a CdTe microcavity. The onset of Bose-Einstein condensation is marked by the disappearance of photon bunching, demonstrating the transition from a thermal-like state to a coherent state. Coherence is, however, degraded with increasing polariton density, most probably as a result of self-interaction within the condensate and scatterings with noncondensed excitons and polaritons. Such behavior clearly differentiates polariton Bose condensation from photon lasing.
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Affiliation(s)
- J Kasprzak
- Institut Néel, CNRS/UJF, 25 avenue des Martyrs, BP 166 38042 Grenoble cedex 9, France
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21
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Wouters M, Carusotto I. Excitations in a nonequilibrium Bose-Einstein condensate of exciton polaritons. PHYSICAL REVIEW LETTERS 2007; 99:140402. [PMID: 17930649 DOI: 10.1103/physrevlett.99.140402] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Indexed: 05/25/2023]
Abstract
We develop a mean-field theory of the dynamics of a nonequilibrium Bose-Einstein condensate of exciton polaritons in a semiconductor microcavity. The spectrum of elementary excitations around the stationary state is analytically studied by means of a generalized Gross-Pitaevskii equation. A diffusive behavior of the Goldstone mode is found in the spatially homogeneous case and new features are predicted for the Josephson effect in a two-well geometry.
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Affiliation(s)
- Michiel Wouters
- TFVS, Universiteit Antwerpen, Groenenborgerlaan 171, 2020, Antwerpen, Belgium
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22
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Deng H, Solomon GS, Hey R, Ploog KH, Yamamoto Y. Spatial coherence of a polariton condensate. PHYSICAL REVIEW LETTERS 2007; 99:126403. [PMID: 17930529 DOI: 10.1103/physrevlett.99.126403] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Indexed: 05/25/2023]
Abstract
We perform Young's double-slit experiment to study the spatial coherence properties of a two-dimensional dynamic condensate of semiconductor microcavity polaritons. The coherence length of the system is measured as a function of the pump rate, which confirms a spontaneous buildup of macroscopic coherence in the condensed phase. An independent measurement reveals that the position and momentum uncertainty product of the condensate is close to the Heisenberg limit. An experimental realization of such a minimum uncertainty wave packet of the polariton condensate opens a door to coherent matter-wave phenomena such as Josephson oscillation, superfluidity, and solitons in solid state condensate systems.
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Affiliation(s)
- Hui Deng
- Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
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23
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Eastham PR. The new physics of non-equilibrium condensates: insights from classical dynamics. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:295210. [PMID: 21483062 DOI: 10.1088/0953-8984/19/29/295210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We discuss the dynamics of classical Dicke-type models, aiming to clarify the mechanisms by which coherent states could develop in potentially non-equilibrium systems such as semiconductor microcavities. We present simulations of an undamped model which show spontaneous coherent states with persistent oscillations in the magnitude of the order parameter. These states are generalizations of superradiant ringing to the case of inhomogeneous broadening. They correspond to the persistent gap oscillations proposed in fermionic atomic condensates, and arise from a variety of initial conditions. We show that introducing randomness into the couplings can suppress the oscillations, leading to a limiting dynamics with a time-independent order parameter. This demonstrates that non-equilibrium generalizations of polariton condensates can be created even without dissipation. We explain the dynamical origins of the coherence in terms of instabilities of the normal state, and consider how it can additionally develop through scattering and dissipation.
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Affiliation(s)
- P R Eastham
- Theory of Condensed Matter, Cavendish Laboratory, Cambridge CB3 0HE, UK
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24
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Christopoulos S, von Högersthal GBH, Grundy AJD, Lagoudakis PG, Kavokin AV, Baumberg JJ, Christmann G, Butté R, Feltin E, Carlin JF, Grandjean N. Room-temperature polariton lasing in semiconductor microcavities. PHYSICAL REVIEW LETTERS 2007; 98:126405. [PMID: 17501142 DOI: 10.1103/physrevlett.98.126405] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Indexed: 05/02/2023]
Abstract
We observe a room-temperature low-threshold transition to a coherent polariton state in bulk GaN microcavities in the strong-coupling regime. Nonresonant pulsed optical pumping produces rapid thermalization and yields a clear emission threshold of 1 mW, corresponding to an absorbed energy density of 29 microJ cm-2, 1 order of magnitude smaller than the best optically pumped (In,Ga)N quantum-well surface-emitting lasers (VCSELs). Angular and spectrally resolved luminescence show that the polariton emission is beamed in the normal direction with an angular width of +/-5 degrees and spatial size around 5 microm.
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Affiliation(s)
- S Christopoulos
- School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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25
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Quinteiro GF, Fernández-Rossier J, Piermarocchi C. Long-range spin-qubit interaction mediated by microcavity polaritons. PHYSICAL REVIEW LETTERS 2006; 97:097401. [PMID: 17026399 DOI: 10.1103/physrevlett.97.097401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Indexed: 05/12/2023]
Abstract
We study the optically induced coupling between spins mediated by polaritons in a planar microcavity. In the strong-coupling regime, the vacuum Rabi splitting introduces anisotropies in the spin coupling. Moreover, due to their photonlike mass, polaritons provide an extremely long spin coupling range. This suggests the realization of two-qubit all-optical quantum operations within tens of picoseconds with spins localized as far as hundreds of nanometers apart.
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Affiliation(s)
- G F Quinteiro
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
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26
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Kasprzak J, Richard M, Kundermann S, Baas A, Jeambrun P, Keeling JMJ, Marchetti FM, Szymańska MH, André R, Staehli JL, Savona V, Littlewood PB, Deveaud B, Dang LS. Bose–Einstein condensation of exciton polaritons. Nature 2006; 443:409-14. [PMID: 17006506 DOI: 10.1038/nature05131] [Citation(s) in RCA: 687] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 07/24/2006] [Indexed: 11/08/2022]
Abstract
Phase transitions to quantum condensed phases--such as Bose-Einstein condensation (BEC), superfluidity, and superconductivity--have long fascinated scientists, as they bring pure quantum effects to a macroscopic scale. BEC has, for example, famously been demonstrated in dilute atom gas of rubidium atoms at temperatures below 200 nanokelvin. Much effort has been devoted to finding a solid-state system in which BEC can take place. Promising candidate systems are semiconductor microcavities, in which photons are confined and strongly coupled to electronic excitations, leading to the creation of exciton polaritons. These bosonic quasi-particles are 10(9) times lighter than rubidium atoms, thus theoretically permitting BEC to occur at standard cryogenic temperatures. Here we detail a comprehensive set of experiments giving compelling evidence for BEC of polaritons. Above a critical density, we observe massive occupation of the ground state developing from a polariton gas at thermal equilibrium at 19 K, an increase of temporal coherence, and the build-up of long-range spatial coherence and linear polarization, all of which indicate the spontaneous onset of a macroscopic quantum phase.
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Affiliation(s)
- J Kasprzak
- CEA-CNRS-UJF joint group Nanophysique et Semiconducteurs, Laboratoire de Spectrométrie Physique, UMR5588, Université J. Fourier-Grenoble, F-38402 Saint Martin d'Hères cedex, France.
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27
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Szymańska MH, Keeling J, Littlewood PB. Nonequilibrium quantum condensation in an incoherently pumped dissipative system. PHYSICAL REVIEW LETTERS 2006; 96:230602. [PMID: 16803361 DOI: 10.1103/physrevlett.96.230602] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2006] [Indexed: 05/10/2023]
Abstract
We study spontaneous quantum coherence in an out of an equilibrium system, coupled to multiple baths describing pumping and decay. For a range of parameters describing coupling to, and occupation of the baths, a stable steady-state condensed solution exists. The presence of pumping and decay significantly modifies the spectra of phase fluctuations, leading to correlation functions that differ both from an isolated condensate and from a laser.
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Affiliation(s)
- M H Szymańska
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
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28
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Marchetti FM, Keeling J, Szymańska MH, Littlewood PB. Thermodynamics and excitations of condensed polaritons in disordered microcavities. PHYSICAL REVIEW LETTERS 2006; 96:066405. [PMID: 16606023 DOI: 10.1103/physrevlett.96.066405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Indexed: 05/08/2023]
Abstract
We study the thermodynamic condensation of microcavity polaritons using a realistic model of disorder in semiconductor quantum wells. This approach correctly describes the polariton inhomogeneous broadening in the low density limit, and treats scattering by disorder to all orders in the condensed regime. While the weak disorder changes the thermodynamic properties of the transition little, the effects of disorder in the condensed state are prominent in the excitations and can be seen in resonant Rayleigh scattering.
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Affiliation(s)
- F M Marchetti
- Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, United Kingdom
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