TY - JOUR A1 - Wurdack, Matthias A1 - Lundt, Nils A1 - Klaas, Martin A1 - Baumann, Vasilij A1 - Kavokin, Alexey V. A1 - Höfling, Sven A1 - Schneider, Christian T1 - Observation of hybrid Tamm-plasmon exciton-polaritons with GaAs quantum wells and a MoSe\(_{2}\) monolayer JF - Nature Communications N2 - Strong light matter coupling between excitons and microcavity photons, as described in the framework of cavity quantum electrodynamics, leads to the hybridization of light and matter excitations. The regime of collective strong coupling arises, when various excitations from different host media are strongly coupled to the same optical resonance. This leads to a well-controllable admixture of various matter components in three hybrid polariton modes. Here, we study a cavity device with four embedded GaAs quantum wells hosting excitons that are spectrally matched to the A-valley exciton resonance of a MoSe\(_{2}\) monolayer. The formation of hybrid polariton modes is evidenced in momentum resolved photoluminescence and reflectivity studies. We describe the energy and k-vector distribution of exciton-polaritons along the hybrid modes by a thermodynamic model, which yields a very good agreement with the experiment. KW - two-dimensional materials KW - microresonators KW - nanophotonics and plasmonics KW - cavity device KW - strong coupling Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170480 VL - 8 IS - 259 ER - TY - JOUR A1 - Heil, Hannah S. A1 - Schreiber, Benjamin A1 - Götz, Ralph A1 - Emmerling, Monika A1 - Dabauvalle, Marie-Christine A1 - Krohne, Georg A1 - Höfling, Sven A1 - Kamp, Martin A1 - Sauer, Markus A1 - Heinze, Katrin G. T1 - Sharpening emitter localization in front of a tuned mirror JF - Light: Science & Applications N2 - Single-molecule localization microscopy (SMLM) aims for maximized precision and a high signal-to-noise ratio1. Both features can be provided by placing the emitter in front of a metal-dielectric nanocoating that acts as a tuned mirror2,3,4. Here, we demonstrate that a higher photon yield at a lower background on biocompatible metal-dielectric nanocoatings substantially improves SMLM performance and increases the localization precision by up to a factor of two. The resolution improvement relies solely on easy-to-fabricate nanocoatings on standard glass coverslips and is spectrally and spatially tunable by the layer design and wavelength, as experimentally demonstrated for dual-color SMLM in cells. KW - imaging and sensing KW - super-resolution microscopy Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228080 VL - 7 ER - TY - JOUR A1 - Schneider, Christian A1 - Glazov, Mikhail M. A1 - Korn, Tobias A1 - Höfling, Sven A1 - Urbaszek, Bernhard T1 - Two-dimensional semiconductors in the regime of strong light-matter coupling JF - Nature Communications N2 - The optical properties of transition metal dichalcogenide monolayers are widely dominated by excitons, Coulomb-bound electron–hole pairs. These quasi-particles exhibit giant oscillator strength and give rise to narrow-band, well-pronounced optical transitions, which can be brought into resonance with electromagnetic fields in microcavities and plasmonic nanostructures. Due to the atomic thinness and robustness of the monolayers, their integration in van der Waals heterostructures provides unique opportunities for engineering strong light-matter coupling. We review first results in this emerging field and outline future opportunities and challenges. KW - optical physics KW - two-dimensional materials Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231295 VL - 9 ER - TY - JOUR A1 - Kreinberg, Sören A1 - Grbešić, Tomislav A1 - Strauß, Max A1 - Carmele, Alexander A1 - Emmerling, Monika A1 - Schneider, Christian A1 - Höfling, Sven A1 - Porte, Xavier A1 - Reitzenstein, Stephan T1 - Quantum-optical spectroscopy of a two-level system using an electrically driven micropillar laser as a resonant excitation source JF - Light: Science & Applications N2 - Two-level emitters are the main building blocks of photonic quantum technologies and are model systems for the exploration of quantum optics in the solid state. Most interesting is the strict resonant excitation of such emitters to control their occupation coherently and to generate close to ideal quantum light, which is of utmost importance for applications in photonic quantum technology. To date, the approaches and experiments in this field have been performed exclusively using bulky lasers, which hinders the application of resonantly driven two-level emitters in compact photonic quantum systems. Here we address this issue and present a concept for a compact resonantly driven single-photon source by performing quantum-optical spectroscopy of a two-level system using a compact high-β microlaser as the excitation source. The two-level system is based on a semiconductor quantum dot (QD), which is excited resonantly by a fiber-coupled electrically driven micropillar laser. We dress the excitonic state of the QD under continuous wave excitation, and trigger the emission of single photons with strong multi-photon suppression (g\(^{(2)}\)(0)=0.02) and high photon indistinguishability (V = 57±9%) via pulsed resonant excitation at 156 MHz. These results clearly demonstrate the high potential of our resonant excitation scheme, which can pave the way for compact electrically driven quantum light sources with excellent quantum properties to enable the implementation of advanced quantum communication protocols. KW - near-infrared spectroscopy KW - photonic devices KW - semiconductor lasers KW - single photons and quantum effects Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229802 VL - 7 ER - TY - JOUR A1 - Waldherr, Max A1 - Lundt, Nils A1 - Klaas, Martin A1 - Betzold, Simon A1 - Wurdack, Matthias A1 - Baumann, Vasilij A1 - Estrecho, Eliezer A1 - Nalitov, Anton A1 - Cherotchenko, Evgenia A1 - Cai, Hui A1 - Ostrovskaya, Elena A. A1 - Kavokin, Alexey V. A1 - Tongay, Sefaattin A1 - Klembt, Sebastian A1 - Höfling, Sven A1 - Schneider, Christian T1 - Observation of bosonic condensation in a hybrid monolayer MoSe2-GaAs microcavity JF - Nature Communications N2 - 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. KW - polaritons KW - two-dimensional materials Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233280 VL - 9 ER - TY - JOUR A1 - Schlottmann, Elisabeth A1 - Schicke, David A1 - Krüger, Felix A1 - Lingnau, Benjamin A1 - Schneider, Christian A1 - Höfling, Sven A1 - Lüdge, Kathy A1 - Porte, Xavier A1 - Reitzenstein, Stephan T1 - Stochastic polarization switching induced by optical injection in bimodal quantum-dot micropillar lasers JF - Optics Express N2 - Mutual coupling and injection locking of semiconductor lasers is of great interest in non-linear dynamics and its applications for instance in secure data communication and photonic reservoir computing. Despite its importance, it has hardly been studied in microlasers operating at mu W light levels. In this context, vertically emitting quantum dot micropillar lasers are of high interest. Usually, their light emission is bimodal, and the gain competition of the associated linearly polarized fundamental emission modes results in complex switching dynamics. We report on selective optical injection into either one of the two fundamental mode components of a bimodal micropillar laser. Both modes can lock to the master laser and influence the non-injected mode by reducing the available gain. We demonstrate that the switching dynamics can be tailored externally via optical injection in very good agreement with our theory based on semi-classical rate equations. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement KW - Nonlinear Dynamics KW - Bistability KW - Generation KW - Subject KW - Regimes KW - Physics KW - Vcsels Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228603 VL - 27 IS - 20 ER - TY - JOUR A1 - Holzinger, Steffen A1 - Schneider, Christian A1 - Höfling, Sven A1 - Porte, Xavier A1 - Reitzenstein, Stephan T1 - Quantum-dot micropillar lasers subject to coherent time-delayed optical feedback from a short external cavity JF - Scientific Reports N2 - We investigate the mode-switching dynamics of an electrically driven bimodal quantum-dot micropillar laser when subject to delayed coherent optical feedback from a short external cavity. We experimentally characterize how the external cavity length, being on the same order than the microlaser’s coherence length, influences the spectral and dynamical properties of the micropillar laser. Moreover, we determine the relaxation oscillation frequency of the micropillar by superimposing optical pulse injection to a dc current. It is found that the optical pulse can be used to disturb the feedback-coupled laser within one roundtrip time in such a way that it reaches the same output power as if no feedback was present. Our results do not only expand the understanding of microlasers when subject to optical feedback from short external cavities, but pave the way towards tailoring the properties of this key nanophotonic system for studies in the quantum regime of self-feedback and its implementation to integrated photonic circuits. KW - nanophotonics and plasmonics KW - photonic devices KW - quantum dots KW - semiconductor lasers Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322485 VL - 9 ER - TY - JOUR A1 - Kreinberg, Sören A1 - Porte, Xavier A1 - Schicke, David A1 - Lingnau, Benjamin A1 - Schneider, Christian A1 - Höfling, Sven A1 - Kanter, Ido A1 - Lüdge, Kathy A1 - Reitzenstein, Stephan T1 - Mutual coupling and synchronization of optically coupled quantum-dot micropillar lasers at ultra-low light levels JF - Nature Communications N2 - Synchronization of coupled oscillators at the transition between classical physics and quantum physics has become an emerging research topic at the crossroads of nonlinear dynamics and nanophotonics. We study this unexplored field by using quantum dot microlasers as optical oscillators. Operating in the regime of cavity quantum electrodynamics (cQED) with an intracavity photon number on the order of 10 and output powers in the 100 nW range, these devices have high β-factors associated with enhanced spontaneous emission noise. We identify synchronization of mutually coupled microlasers via frequency locking associated with a sub-gigahertz locking range. A theoretical analysis of the coupling behavior reveals striking differences from optical synchronization in the classical domain with negligible spontaneous emission noise. Beyond that, additional self-feedback leads to zero-lag synchronization of coupled microlasers at ultra-low light levels. Our work has high potential to pave the way for future experiments in the quantum regime of synchronization. KW - nanoscale devices KW - quantum optics KW - semiconductor lasers Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229811 VL - 10 ER - TY - JOUR A1 - van Loock, Peter A1 - Alt, Wolfgang A1 - Becher, Christoph A1 - Benson, Oliver A1 - Boche, Holger A1 - Deppe, Christian A1 - Eschner, Jürgen A1 - Höfling, Sven A1 - Meschede, Dieter A1 - Michler, Peter A1 - Schmidt, Frank A1 - Weinfurter, Harald T1 - Extending Quantum Links: Modules for Fiber‐ and Memory‐Based Quantum Repeaters JF - Advanced Quantum Technologies N2 - Elementary building blocks for quantum repeaters based on fiber channels and memory stations are analyzed. Implementations are considered for three different physical platforms, for which suitable components are available: quantum dots, trapped atoms and ions, and color centers in diamond. The performances of basic quantum repeater links for these platforms are evaluated and compared, both for present‐day, state‐of‐the‐art experimental parameters as well as for parameters that can in principle be reached in the future. The ultimate goal is to experimentally explore regimes at intermediate distances—up to a few 100 km—in which the repeater‐assisted secret key transmission rates exceed the maximal rate achievable via direct transmission. Two different protocols are considered, one of which is better adapted to the higher source clock rate and lower memory coherence time of the quantum dot platform, while the other circumvents the need of writing photonic quantum states into the memories in a heralded, nondestructive fashion. The elementary building blocks and protocols can be connected in a modular form to construct a quantum repeater system that is potentially scalable to large distances. KW - color centers KW - quantum communication KW - quantum dots KW - quantum repeaters KW - trapped atoms/ions Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228322 VL - 3 IS - 11 ER - TY - JOUR A1 - Wyborski, Paweł A1 - Musiał, Anna A1 - Mrowiński, Paweł A1 - Podemski, Paweł A1 - Baumann, Vasilij A1 - Wroński, Piotr A1 - Jabeen, Fauzia A1 - Höfling, Sven A1 - Sęk, Grzegorz T1 - InP-substrate-based quantum dashes on a DBR as single-photon emitters at the third telecommunication window JF - Materials N2 - We investigated emission properties of photonic structures with InAs/InGaAlAs/InP quantum dashes grown by molecular beam epitaxy on a distributed Bragg reflector. In high-spatial-resolution photoluminescence experiment, well-resolved sharp spectral lines are observed and single-photon emission is detected in the third telecommunication window characterized by very low multiphoton events probabilities. The photoluminescence spectra measured on simple photonic structures in the form of cylindrical mesas reveal significant intensity enhancement by a factor of 4 when compared to a planar sample. These results are supported by simulations of the electromagnetic field distribution, which show emission extraction efficiencies even above 18% for optimized designs. When combined with relatively simple and undemanding fabrication approach, it makes this kind of structures competitive with the existing solutions in that spectral range and prospective in the context of efficient and practical single-photon sources for fiber-based quantum networks applications. KW - single-photon emitter KW - III–V quantum dot KW - telecommunication spectral range KW - photonic structure KW - extraction efficiency Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228773 SN - 1996-1944 VL - 14 IS - 4 ER -