1
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Zhu C, Nguyen T, Boehme SC, Moskalenko A, Dirin DN, Bodnarchuk MI, Katan C, Even J, Rainò G, Kovalenko MV. Many-Body Correlations and Exciton Complexes in CsPbBr 3 Quantum Dots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208354. [PMID: 36537857 DOI: 10.1002/adma.202208354] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/25/2022] [Indexed: 06/17/2023]
Abstract
All-inorganic lead-halide perovskite (LHP) (CsPbX3 , X = Cl, Br, I) quantum dots (QDs) have emerged as a competitive platform for classical light-emitting devices (in the weak light-matter interaction regime, e.g., LEDs and laser), as well as for devices exploiting strong light-matter interaction at room temperature. Many-body interactions and quantum correlations among photogenerated exciton complexes play an essential role, for example, by determining the laser threshold, the overall brightness of LEDs, and the single-photon purity in quantum light sources. Here, by combining cryogenic single-QD photoluminescence spectroscopy with configuration-interaction (CI) calculations, the size-dependent trion and biexciton binding energies are addressed. Trion binding energies increase from 7 to 17 meV for QD sizes decreasing from 30 to 9 nm, while the biexciton binding energies increase from 15 to 30 meV, respectively. CI calculations quantitatively corroborate the experimental results and suggest that the effective dielectric constant for biexcitons slightly deviates from the one of the single excitons, potentially as a result of coupling to the lattice in the multiexciton regime. The findings here provide a deep insight into the multiexciton properties in all-inorganic LHP QDs, essential for classical and quantum optoelectronic devices.
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Affiliation(s)
- Chenglian Zhu
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Tan Nguyen
- Univ Rennes, ENSCR, CNRS, ISCR - UMR6226, Rennes, F-35000, France
| | - Simon C Boehme
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Anastasiia Moskalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Dmitry N Dirin
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Maryna I Bodnarchuk
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Claudine Katan
- Univ Rennes, ENSCR, CNRS, ISCR - UMR6226, Rennes, F-35000, France
| | - Jacky Even
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON - UMR6082, Rennes, F-35000, France
| | - Gabriele Rainò
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Maksym V Kovalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
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2
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Tuktamyshev A, Vichi S, Cesura FG, Fedorov A, Carminati G, Lambardi D, Pedrini J, Vitiello E, Pezzoli F, Bietti S, Sanguinetti S. Strain Relaxation of InAs Quantum Dots on Misoriented InAlAs(111) Metamorphic Substrates. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3571. [PMID: 36296766 PMCID: PMC9607536 DOI: 10.3390/nano12203571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 09/27/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
We investigate in detail the role of strain relaxation and capping overgrowth in the self-assembly of InAs quantum dots by droplet epitaxy. InAs quantum dots were realized on an In0.6Al0.4As metamorphic buffer layer grown on a GaAs(111)A misoriented substrate. The comparison between the quantum electronic calculations of the optical transitions and the emission properties of the quantum dots highlights the presence of a strong quenching of the emission from larger quantum dots. Detailed analysis of the surface morphology during the capping procedure show the presence of a critical size over which the quantum dots are plastically relaxed.
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Affiliation(s)
- Artur Tuktamyshev
- Isituto Nazionale di Fisica Nucleare, Sezione di Milano-Bicocca, 20100 Milano, Italy
| | - Stefano Vichi
- Isituto Nazionale di Fisica Nucleare, Sezione di Milano-Bicocca, 20100 Milano, Italy
| | | | - Alexey Fedorov
- Centro Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, 20100 Milano, Italy
| | - Giuseppe Carminati
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Davide Lambardi
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Jacopo Pedrini
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Elisa Vitiello
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Fabio Pezzoli
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Sergio Bietti
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Stefano Sanguinetti
- Isituto Nazionale di Fisica Nucleare, Sezione di Milano-Bicocca, 20100 Milano, Italy
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
- Centro Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, 20100 Milano, Italy
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3
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Varo S, Juska G, Pelucchi E. An intuitive protocol for polarization-entanglement restoral of quantum dot photon sources with non-vanishing fine-structure splitting. Sci Rep 2022; 12:4723. [PMID: 35304526 PMCID: PMC8933574 DOI: 10.1038/s41598-022-08535-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 03/02/2022] [Indexed: 11/10/2022] Open
Abstract
Generation of polarization-entangled photons from quantum dots via the biexciton-exciton recombination cascade is complicated by the presence of an energy splitting between the intermediate excitonic levels, which severely degrades the quality of the entangled photon source. In this paper we present a novel, conceptually simple and straightforward proposal for restoring the entanglement of said source by applying a cascade of time-dependent operations on the emitted photons. This is in striking contrast with the techniques usually employed, that act on the quantum emitter itself in order to remove the fine structure splitting at its root. The feasibility of the implementation with current technology is discussed, and the robustness of the proposed compensation scheme with respect to imperfections of the experimental apparatus is evaluated via a series of Monte Carlo simulations.
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Affiliation(s)
- Simone Varo
- Tyndall National Institute, University College Cork, Dyke Parade, Cork, Republic of Ireland.
| | - Gediminas Juska
- Tyndall National Institute, University College Cork, Dyke Parade, Cork, Republic of Ireland
| | - Emanuele Pelucchi
- Tyndall National Institute, University College Cork, Dyke Parade, Cork, Republic of Ireland
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4
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Tuktamyshev A, Fedorov A, Bietti S, Vichi S, Tambone R, Tsukamoto S, Sanguinetti S. Nucleation of Ga droplets self-assembly on GaAs(111)A substrates. Sci Rep 2021; 11:6833. [PMID: 33767304 PMCID: PMC7994575 DOI: 10.1038/s41598-021-86339-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 03/15/2021] [Indexed: 11/10/2022] Open
Abstract
We investigated the nucleation of Ga droplets on singular GaAs(111)A substrates in the view of their use as the seeds for the self-assembled droplet epitaxial quantum dots. A small critical cluster size of 1–2 atoms characterizes the droplet nucleation. Low values of the Hopkins-Skellam index (as low as 0.35) demonstrate a high degree of a spatial order of the droplet ensemble. Around \documentclass[12pt]{minimal}
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\begin{document}$$350\,^{\circ }\hbox {C}$$\end{document}350∘C the droplet size distribution becomes bimodal. We attribute this observation to the interplay between the local environment and the limitation to the adatom surface diffusion introduced by the Ehrlich–Schwöbel barrier at the terrace edges.
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Affiliation(s)
- Artur Tuktamyshev
- Department of Material Science, University of Milano-Bicocca, via R. Cozzi 55, 20125, Milan, Italy. .,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy.
| | - Alexey Fedorov
- CNR Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy
| | - Sergio Bietti
- Department of Material Science, University of Milano-Bicocca, via R. Cozzi 55, 20125, Milan, Italy.,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy
| | - Stefano Vichi
- Department of Material Science, University of Milano-Bicocca, via R. Cozzi 55, 20125, Milan, Italy.,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy
| | - Riccardo Tambone
- Department of Material Science, University of Milano-Bicocca, via R. Cozzi 55, 20125, Milan, Italy.,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy
| | - Shiro Tsukamoto
- Department of Material Science, University of Milano-Bicocca, via R. Cozzi 55, 20125, Milan, Italy.,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy
| | - Stefano Sanguinetti
- Department of Material Science, University of Milano-Bicocca, via R. Cozzi 55, 20125, Milan, Italy.,Laboratory for Nanostructure Epitaxy and Spintronics on Silicon, Polo di Como, via F. Anzani 42, 22100, Como, Italy
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5
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Li X. The structural symmetry of nanoholes upon droplet epitaxy. NANOTECHNOLOGY 2021; 32:225602. [PMID: 33631728 DOI: 10.1088/1361-6528/abe9e5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
Nanoholes obtained by droplet epitaxy has been intensively investigated as an important material platform for the fabrication of nanodevices due to their unique topology. However, the final fabricated nanoholes are very difficult to achieve a highly symmetric circular structure, and usually have two or four gaps in the sidewall of the holes. Here we have presented a developed model to inquire into the reasons for the formation of the gaps at the periphery of nanoholes and discuss how to improve the structural symmetry of the nanoholes. It is found that the anisotropic interface diffusion of As atoms decomposed by substrate can result in the formation of the gaps. In order to improve the symmetry of final nanostructures, we can minimize the interval time between deposition of Ga droplets and open operation of As flux, and set up a multistep growth procedure by changing the intensity of As flux or growth temperature.
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Affiliation(s)
- Xinlei Li
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, People's Republic of China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, People's Republic of China
- Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, People's Republic of China
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6
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Abbarchi M, Mano T, Kuroda T, Ohtake A, Sakoda K. Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:443. [PMID: 33578657 PMCID: PMC7916409 DOI: 10.3390/nano11020443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 11/17/2022]
Abstract
We provide an extensive and systematic investigation of exciton dynamics in droplet epitaxial quantum dots comparing the cases of (311)A, (001), and (111)A surfaces. Despite a similar s-shell exciton structure common to the three cases, the absence of a wetting layer for (311)A and (111)A samples leads to a larger carrier confinement compared to (001), where a wetting layer is present. This leads to a more pronounced dependence of the binding energies of s-shell excitons on the quantum dot size and to the strong anti-binding character of the positive-charged exciton for smaller quantum dots. In-plane geometrical anisotropies of (311)A and (001) quantum dots lead to a large electron-hole fine interaction (fine structure splitting (FSS) ∼100 μeV), whereas for the three-fold symmetric (111)A counterpart, this figure of merit is reduced by about one order of magnitude. In all these cases, we do not observe any size dependence of the fine structure splitting. Heavy-hole/light-hole mixing is present in all the studied cases, leading to a broad spread of linear polarization anisotropy (from 0 up to about 50%) irrespective of surface orientation (symmetry of the confinement), fine structure splitting, and nanostructure size. These results are important for the further development of ideal single and entangled photon sources based on semiconductor quantum dots.
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Affiliation(s)
- Marco Abbarchi
- Aix Marseille Univ, Université de Toulon, CNRS, IM2NP Marseille, France
| | - Takaaki Mano
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (A.O.); (K.S.)
| | - Takashi Kuroda
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (A.O.); (K.S.)
| | - Akihiro Ohtake
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (A.O.); (K.S.)
| | - Kazuaki Sakoda
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (A.O.); (K.S.)
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7
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Aarts M, van Vliet S, Bliem R, Alarcon-Llado E. Investigation of copper nanoscale electro-crystallization under directed and non-directed electrodeposition from dilute electrolytes. CrystEngComm 2021. [DOI: 10.1039/d1ce00143d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ and ex situ atomic force microscopy was used to investigate crystal growth in copper electro-crystallization localized and directed by a moving nanoelectrode in close proximity to a gold substrate in a highly dilute electrolyte.
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Affiliation(s)
- Mark Aarts
- Center for Nanophotonics
- AMOLF
- Amsterdam
- Netherlands
| | | | - Roland Bliem
- Advanced Center for Nanolithography
- ARCNL
- Amsterdam
- Netherlands
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8
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Zhai L, Löbl MC, Nguyen GN, Ritzmann J, Javadi A, Spinnler C, Wieck AD, Ludwig A, Warburton RJ. Low-noise GaAs quantum dots for quantum photonics. Nat Commun 2020; 11:4745. [PMID: 32958795 PMCID: PMC7506537 DOI: 10.1038/s41467-020-18625-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 09/03/2020] [Indexed: 11/18/2022] Open
Abstract
Quantum dots are both excellent single-photon sources and hosts for single spins. This combination enables the deterministic generation of Raman-photons—bandwidth-matched to an atomic quantum-memory—and the generation of photon cluster states, a resource in quantum communication and measurement-based quantum computing. GaAs quantum dots in AlGaAs can be matched in frequency to a rubidium-based photon memory, and have potentially improved electron spin coherence compared to the widely used InGaAs quantum dots. However, their charge stability and optical linewidths are typically much worse than for their InGaAs counterparts. Here, we embed GaAs quantum dots into an n-i-p-diode specially designed for low-temperature operation. We demonstrate ultra-low noise behaviour: charge control via Coulomb blockade, close-to lifetime-limited linewidths, and no blinking. We observe high-fidelity optical electron-spin initialisation and long electron-spin lifetimes for these quantum dots. Our work establishes a materials platform for low-noise quantum photonics close to the red part of the spectrum. GaAs quantum dots emitting at the near-red part of the spectrum usually suffers from excess charge-noise. With a careful design of a n-i-p-diode structure hosting GaAs quantum dots, the authors demonstrate ultralow-noise behaviour and high-fidelity spin initialisation close to rubidium wavelengths.
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Affiliation(s)
- Liang Zhai
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
| | - Matthias C Löbl
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Giang N Nguyen
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.,Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Julian Ritzmann
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Alisa Javadi
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Clemens Spinnler
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Richard J Warburton
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
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9
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Abbarchi M, Mano T, Kuroda T, Sakoda K. Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A-Oriented Substrates. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1833. [PMID: 32937876 PMCID: PMC7558330 DOI: 10.3390/nano10091833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 12/16/2022]
Abstract
Droplet epitaxy allows the efficient fabrication of a plethora of 3D, III-V-based nanostructures on different crystalline orientations. Quantum dots grown on a (311)A-oriented surface are obtained with record surface density, with or without a wetting layer. These are appealing features for quantum dot lasing, thanks to the large density of quantum emitters and a truly 3D lateral confinement. However, the intimate photophysics of this class of nanostructures has not yet been investigated. Here, we address the main optical and electronic properties of s-shell excitons in individual quantum dots grown on (311)A substrates with photoluminescence spectroscopy experiments. We show the presence of neutral exciton and biexciton as well as positive and negative charged excitons. We investigate the origins of spectral broadening, identifying them in spectral diffusion at low temperature and phonon interaction at higher temperature, the presence of fine interactions between electron and hole spin, and a relevant heavy-hole/light-hole mixing. We interpret the level filling with a simple Poissonian model reproducing the power excitation dependence of the s-shell excitons. These results are relevant for the further improvement of this class of quantum emitters and their exploitation as single-photon sources for low-density samples as well as for efficient lasers for high-density samples.
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Affiliation(s)
- Marco Abbarchi
- Aix Marseille University, Université de Toulon, CNRS, IM2NP Marseille, France
| | - Takaaki Mano
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (K.S.)
| | - Takashi Kuroda
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (K.S.)
| | - Kazuaki Sakoda
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; (T.M.); (T.K.); (K.S.)
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10
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Reentrant Behavior of the Density vs. Temperature of Indium Islands on GaAs(111)A. NANOMATERIALS 2020; 10:nano10081512. [PMID: 32752124 PMCID: PMC7466431 DOI: 10.3390/nano10081512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/24/2020] [Accepted: 07/29/2020] [Indexed: 11/17/2022]
Abstract
We show that the density of indium islands on GaAs(111)A substrates have a non-monotonic, reentrant behavior as a function of the indium deposition temperature. The expected increase in the density with decreasing temperature, indeed, is observed only down to 160 ∘C, where the indium islands undertake the expected liquid-to-solid phase transition. Further decreasing the temperature causes a sizable reduction of the island density. An additional reentrant increasing behavior is observed below 80 ∘C. We attribute the above complex behavior to the liquid-solid phase transition and to the complex island-island interaction which takes place between crystalline islands in the presence of strain. Indium solid islands grown at temperatures below 160 ∘C have a face-centered cubic crystal structure.
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11
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Yeo I, Kim D, Lee KT, Kim JS, Song JD, Park CH, Han IK. Comparative Chemico-Physical Analyses of Strain-Free GaAs/Al 0.3Ga 0.7As Quantum Dots Grown by Droplet Epitaxy. NANOMATERIALS 2020; 10:nano10071301. [PMID: 32630839 PMCID: PMC7407363 DOI: 10.3390/nano10071301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/16/2022]
Abstract
We investigate the quantum confinement effects on excitons in several types of strain-free GaAs/Al 0 . 3 Ga 0 . 7 As droplet epitaxy (DE) quantum dots (QDs). By performing comparative analyses of energy-dispersive X-ray spectroscopy with the aid of a three-dimensional (3D) envelope-function model, we elucidate the individual quantum confinement characteristics of the QD band structures with respect to their composition profiles and the asymmetries of their geometrical shapes. By precisely controlling the exciton oscillator strength in strain-free QDs, we envisage the possibility of tailoring light-matter interactions to implement fully integrated quantum photonics based on QD single-photon sources (SPSs).
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Affiliation(s)
- Inah Yeo
- Dielectrics and Advanced Matter Physics Research Center, Pusan National University, Busan 46241, Korea; (D.K.); (C.-H.P.)
- Correspondence: (I.Y.); (I.K.H.)
| | - Doukyun Kim
- Dielectrics and Advanced Matter Physics Research Center, Pusan National University, Busan 46241, Korea; (D.K.); (C.-H.P.)
| | - Kyu-Tae Lee
- Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea;
| | - Jong Su Kim
- Department of Physics, Yeungnam University, Gyeonsan 38541, Korea;
| | - Jin Dong Song
- Post-Silicon Semiconductor Institute, Korea Institute of Science and Technology, Seoul 02792, Korea;
| | - Chul-Hong Park
- Dielectrics and Advanced Matter Physics Research Center, Pusan National University, Busan 46241, Korea; (D.K.); (C.-H.P.)
| | - Il Ki Han
- Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea;
- Correspondence: (I.Y.); (I.K.H.)
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12
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High-temperature droplet epitaxy of symmetric GaAs/AlGaAs quantum dots. Sci Rep 2020; 10:6532. [PMID: 32300114 PMCID: PMC7162903 DOI: 10.1038/s41598-020-62248-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/02/2020] [Indexed: 11/08/2022] Open
Abstract
We introduce a high-temperature droplet epitaxy procedure, based on the control of the arsenization dynamics of nanoscale droplets of liquid Ga on GaAs(111)A surfaces. The use of high temperatures for the self-assembly of droplet epitaxy quantum dots solves major issues related to material defects, introduced during the droplet epitaxy fabrication process, which limited its use for single and entangled photon sources for quantum photonics applications. We identify the region in the parameter space which allows quantum dots to self-assemble with the desired emission wavelength and highly symmetric shape while maintaining a high optical quality. The role of the growth parameters during the droplet arsenization is discussed and modeled.
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13
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Vichi S, Bietti S, Khalili A, Costanzo M, Cappelluti F, Esposito L, Somaschini C, Fedorov A, Tsukamoto S, Rauter P, Sanguinetti S. Droplet epitaxy quantum dot based infrared photodetectors. NANOTECHNOLOGY 2020; 31:245203. [PMID: 32106107 DOI: 10.1088/1361-6528/ab7aa6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The fabrication and characterization of an infrared photodetector based on GaAs droplet epitaxy quantum dots embedded in Al0.3Ga0.7As barrier is reported. The high control over dot electronic properties and the high achievable number density allowed by droplet epitaxy technique permitted us to realize a device using a single dot layer in the active region. Moreover, thanks to the independent control over dot height and width, we were able to obtain a very sharp absorption peak in the thermal infrared region (3-8 μm). Low temperature photocurrent spectrum was measured by Fourier spectroscopy, showing a narrow peak at 198 meV (∼6.3 μm) with a full width at half maximum of 25 meV. The observed absorption is in agreement with theoretical prediction based on effective mass approximation of the dot electronic transition.
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Affiliation(s)
- Stefano Vichi
- LNESS and Department of Materials Science, University of Milano-Bicocca, via Cozzi 55, 20125 Milano, Italy
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14
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Zhao TM, Chen Y, Yu Y, Li Q, Davanco M, Liu J. Advanced technologies for quantum photonic devices based on epitaxial quantum dots. ADVANCED QUANTUM TECHNOLOGIES 2020; 3:10.1002/qute.201900034. [PMID: 36452403 PMCID: PMC9706462 DOI: 10.1002/qute.201900034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Indexed: 05/12/2023]
Abstract
Quantum photonic devices are candidates for realizing practical quantum computers and networks. The development of integrated quantum photonic devices can greatly benefit from the ability to incorporate different types of materials with complementary, superior optical or electrical properties on a single chip. Semiconductor quantum dots (QDs) serve as a core element in the emerging modern photonic quantum technologies by allowing on-demand generation of single-photons and entangled photon pairs. During each excitation cycle, there is one and only one emitted photon or photon pair. QD photonic devices are on the verge of unfolding for advanced quantum technology applications. In this review, we focus on the latest significant progress of QD photonic devices. We first discuss advanced technologies in QD growth, with special attention to droplet epitaxy and site-controlled QDs. Then we overview the wavelength engineering of QDs via strain tuning and quantum frequency conversion techniques. We extend our discussion to advanced optical excitation techniques recently developed for achieving the desired emission properties of QDs. Finally, the advances in heterogeneous integration of active quantum light-emitting devices and passive integrated photonic circuits are reviewed, in the context of realizing scalable quantum information processing chips.
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Affiliation(s)
- Tian Ming Zhao
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Yan Chen
- Institute for Integrative Nanosciences, Leibniz IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Ying Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Qing Li
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Marcelo Davanco
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jin Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
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15
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Yeo I, Kim D, Han IK, Song JD. Strain-induced control of a pillar cavity-GaAs single quantum dot photon source. Sci Rep 2019; 9:18564. [PMID: 31811212 PMCID: PMC6897991 DOI: 10.1038/s41598-019-55010-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/20/2019] [Indexed: 11/09/2022] Open
Abstract
Herein, we present the calculated strain-induced control of single GaAs/AlGaAs quantum dots (QDs) integrated into semiconductor micropillar cavities. We show precise energy control of individual single GaAs QD excitons under multi-modal stress fields of tailored micropillar optomechanical resonators. Further, using a three-dimensional envelope-function model, we evaluated the quantum mechanical correction in the QD band structures depending on their geometrical shape asymmetries and, more interestingly, on the practical degree of Al interdiffusion. Our theoretical calculations provide the practical quantum error margins, obtained by evaluating Al-interdiffused QDs that were engineered through a front-edge droplet epitaxy technique, for tuning engineered QD single-photon sources, facilitating a scalable on-chip integration of QD entangled photons.
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Affiliation(s)
- Inah Yeo
- Dielectrics and Advanced Matter Physics Research Center, Pusan National University, Busan, 46241, Korea.
| | - Doukyun Kim
- Dielectrics and Advanced Matter Physics Research Center, Pusan National University, Busan, 46241, Korea
| | - Il Ki Han
- Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - Jin Dong Song
- Post-Silicon Semiconductor Institute, Korea Institute of Science and Technology, Seoul, 02792, Korea
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16
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Yu Y, Zhong H, Yang J, Liu L, Liu J, Yu S. Highly uniform and symmetric epitaxial InAs quantum dots embedded inside Indium droplet etched nanoholes. NANOTECHNOLOGY 2019; 30:485001. [PMID: 31469109 DOI: 10.1088/1361-6528/ab3efb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
III-V semiconductor quantum dots (QDs) obtained by local droplet etching technology provide a material platform for generation of non-classic light. However, using this technique to fabricate single emitters for a broad spectral range remains a significant challenge. Herein, we successfully extend the QD emission wavelength to 850-880 nm via highly uniform and symmetric InAs QDs located inside indium-droplet-etching nanoholes. The evolution of InGaAs nanostructures by high temperature indium droplet epitaxy on GaAs substrate is revealed. By carefully designing the appropriate growth conditions, symmetric QDs with the a small fine structure splitting of only ∼4.4 ± 0.8 μeV are demonstrated. Averaging over the emission energies of 32 QDs, an ensemble broadening of 12 meV is observed. Individual QDs are shown to emit nonclassically with clear evidence of photon antibunching. These highly uniform and symmetric nanostructures represent a very promising novel strategy for quantum information applications.
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Affiliation(s)
- Ying Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, School of Physics, Sun Yat-sen University, Guangzhou 510275, People's Republic of China. Institute for Quantum Information & State Key Laboratory of High Performance Computing, College of Computer, National University of Defense Technology, Changsha, 410073, People's Republic of China
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17
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Basso Basset F, Rota MB, Schimpf C, Tedeschi D, Zeuner KD, Covre da Silva SF, Reindl M, Zwiller V, Jöns KD, Rastelli A, Trotta R. Entanglement Swapping with Photons Generated on Demand by a Quantum Dot. PHYSICAL REVIEW LETTERS 2019; 123:160501. [PMID: 31702339 DOI: 10.1103/physrevlett.123.160501] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 06/10/2023]
Abstract
Photonic entanglement swapping, the procedure of entangling photons without any direct interaction, is a fundamental test of quantum mechanics and an essential resource to the realization of quantum networks. Probabilistic sources of nonclassical light were used for seminal demonstration of entanglement swapping, but applications in quantum technologies demand push-button operation requiring single quantum emitters. This, however, turned out to be an extraordinary challenge due to the stringent prerequisites on the efficiency and purity of the generation of entangled states. Here we show a proof-of-concept demonstration of all-photonic entanglement swapping with pairs of polarization-entangled photons generated on demand by a GaAs quantum dot without spectral and temporal filtering. Moreover, we develop a theoretical model that quantitatively reproduces the experimental data and provides insights on the critical figures of merit for the performance of the swapping operation. Our theoretical analysis also indicates how to improve state-of-the-art entangled-photon sources to meet the requirements needed for implementation of quantum dots in long-distance quantum communication protocols.
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Affiliation(s)
- F Basso Basset
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - M B Rota
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - C Schimpf
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - D Tedeschi
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - K D Zeuner
- Department of Applied Physics, Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - S F Covre da Silva
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - M Reindl
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - V Zwiller
- Department of Applied Physics, Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - K D Jöns
- Department of Applied Physics, Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - A Rastelli
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - R Trotta
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
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18
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Tuktamyshev A, Fedorov A, Bietti S, Tsukamoto S, Sanguinetti S. Temperature Activated Dimensionality Crossover in the Nucleation of Quantum Dots by Droplet Epitaxy on GaAs(111)A Vicinal Substrates. Sci Rep 2019; 9:14520. [PMID: 31601913 PMCID: PMC6787194 DOI: 10.1038/s41598-019-51161-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/11/2019] [Indexed: 11/10/2022] Open
Abstract
A temperature activated crossover between two nucleation regimes is observed in the behavior of Ga droplet nucleation on vicinal GaAs(111)A substrates with a miscut of 2° towards \documentclass[12pt]{minimal}
\usepackage{amsmath}
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\begin{document}$$(\bar{1}\bar{1}2)$$\end{document}(1¯1¯2). At low temperature (<400 °C) the droplet density dependence on temperature and flux is compatible with droplet nucleation by two-dimensional diffusion. Increasing the temperature, a different regime is observed, whose scaling behavior is compatible with a reduction of the dimensionality of the nucleation regime from two to one dimension. We attribute such behavior to a presence of finite width terraces and a sizeable Ehrlich-Schwöbel barrier at the terrace edge, which hinders adatom diffusion in the direction perpendicular to the steps.
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Affiliation(s)
- Artur Tuktamyshev
- L-NESS and Department of Material Science, University of Milano-Bicocca, Milano, 20125, Italy.
| | | | - Sergio Bietti
- L-NESS and Department of Material Science, University of Milano-Bicocca, Milano, 20125, Italy
| | - Shiro Tsukamoto
- L-NESS and Department of Material Science, University of Milano-Bicocca, Milano, 20125, Italy
| | - Stefano Sanguinetti
- L-NESS and Department of Material Science, University of Milano-Bicocca, Milano, 20125, Italy
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Gurioli M, Wang Z, Rastelli A, Kuroda T, Sanguinetti S. Droplet epitaxy of semiconductor nanostructures for quantum photonic devices. NATURE MATERIALS 2019; 18:799-810. [PMID: 31086322 DOI: 10.1038/s41563-019-0355-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 03/22/2019] [Indexed: 05/25/2023]
Abstract
The long dreamed 'quantum internet' would consist of a network of quantum nodes (solid-state or atomic systems) linked by flying qubits, naturally based on photons, travelling over long distances at the speed of light, with negligible decoherence. A key component is a light source, able to provide single or entangled photon pairs. Among the different platforms, semiconductor quantum dots (QDs) are very attractive, as they can be integrated with other photonic and electronic components in miniaturized chips. In the early 1990s two approaches were developed to synthetize self-assembled epitaxial semiconductor QDs, or 'artificial atoms'-namely, the Stranski-Krastanov (SK) and the droplet epitaxy (DE) methods. Because of its robustness and simplicity, the SK method became the workhorse to achieve several breakthroughs in both fundamental and technological areas. The need for specific emission wavelengths or structural and optical properties has nevertheless motivated further research on the DE method and its more recent development, local droplet etching (LDE), as complementary routes to obtain high-quality semiconductor nanostructures. The recent reports on the generation of highly entangled photon pairs, combined with good photon indistinguishability, suggest that DE and LDE QDs may complement (and sometimes even outperform) conventional SK InGaAs QDs as quantum emitters. We present here a critical survey of the state of the art of DE and LDE, highlighting the advantages and weaknesses, the achievements and challenges that are still open, in view of applications in quantum communication and technology.
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Affiliation(s)
| | - Zhiming Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China
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20
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Yeo I, Yi KS, Lee EH, Song JD, Kim JS, Han IK. Post-thermal-Induced Recrystallization in GaAs/Al 0.3Ga 0.7As Quantum Dots Grown by Droplet Epitaxy with Near-Unity Stoichiometry. ACS OMEGA 2018; 3:8677-8682. [PMID: 31458998 PMCID: PMC6644783 DOI: 10.1021/acsomega.8b01078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/26/2018] [Indexed: 06/10/2023]
Abstract
Here, we investigate the stoichiometry control of GaAs/Al0.3Ga0.7As droplet epitaxy (DE) quantum dots (QDs). Few tens of core nonstoichiometries in the Ga(As) atomic percent are revealed in as-grown "strain-free" QDs using state-of-the-art atomic-scale energy-dispersive X-ray spectroscopy based on transmission electron microscopy. Precise systematic analyses demonstrate a successful quenching of the nonstoichiometry below 2%. The control of the chemical reactions with well-controlled ex situ annealing sheds light on the engineering of a novel single-photon source of strain-free DE QDs free of defects.
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Affiliation(s)
- Inah Yeo
- Post-Silicon
Semiconductor Institute and Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Kyung Soo Yi
- Department
of Physics, Pusan National University, Busan 46241, Korea
| | - Eun Hye Lee
- Post-Silicon
Semiconductor Institute and Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Jin Dong Song
- Post-Silicon
Semiconductor Institute and Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Jong Su Kim
- Department
of Physics, Yeungnam University, Gyeonsan 38541, Korea
| | - Il Ki Han
- Post-Silicon
Semiconductor Institute and Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Korea
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21
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Huber D, Reindl M, Covre da Silva SF, Schimpf C, Martín-Sánchez J, Huang H, Piredda G, Edlinger J, Rastelli A, Trotta R. Strain-Tunable GaAs Quantum Dot: A Nearly Dephasing-Free Source of Entangled Photon Pairs on Demand. PHYSICAL REVIEW LETTERS 2018; 121:033902. [PMID: 30085806 DOI: 10.1103/physrevlett.121.033902] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Indexed: 05/28/2023]
Abstract
We report on the observation of nearly maximally entangled photon pairs from semiconductor quantum dots, without resorting to postselection techniques. We use GaAs quantum dots integrated on a patterned piezoelectric actuator capable of suppressing the exciton fine structure splitting. By using a resonant two-photon excitation, we coherently drive the biexciton state and demonstrate experimentally that our device generates polarization-entangled photons with a fidelity of 0.978(5) and a concurrence of 0.97(1) taking into account the nonidealities stemming from the experimental setup. By combining fine-structure-dependent fidelity measurements and a theoretical model, we identify an exciton spin-scattering process as a possible residual decoherence mechanism. We suggest that this imperfection may be overcome using a modest Purcell enhancement so as to achieve fidelities >0.99, thus making quantum dots evenly matched with the best probabilistic entangled photon sources.
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Affiliation(s)
- Daniel Huber
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
| | - Marcus Reindl
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
| | - Saimon Filipe Covre da Silva
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
| | - Christian Schimpf
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
| | - Javier Martín-Sánchez
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
- Department of Physics, University of Oviedo, 33007 Oviedo, Spain
| | - Huiying Huang
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
| | - Giovanni Piredda
- Forschungszentrum Mikrotechnik, FH Vorarlberg, Hochschulstraße 1, A-6850 Dornbirn, Austria
| | - Johannes Edlinger
- Forschungszentrum Mikrotechnik, FH Vorarlberg, Hochschulstraße 1, A-6850 Dornbirn, Austria
| | - Armando Rastelli
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
| | - Rinaldo Trotta
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Altenbergerstraße 69, 4040, Austria
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
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