Download or read book Deterministic Cavity quantum Dot Coupling and Fabrication of an Ultrabright Source of Entangled Photon Pairs written by Adrien Dousse and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cavity Quantum Electrodynamics with Quantum Dot Photonic Crystal Nanocavities written by Joshua Hendrickson and published by . This book was released on 2010 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: High quality factor, small mode volume photonic crystal cavities and single emitter quantum dots are the topic of this dissertation. They are studied as both a combined system with InAs quantum dots grown in the center of a 2D GaAs photonic crystal slab nanocavity as well as individually. The individual studies are concerned with passive 1D silicon photonic crystal nanobeam cavities and deterministic, site-selectively grown arrays of InAs quantum dots. For the combined system, strong light matter coupling in a quantum dot photonic crystal slab nanocavity is discussed. Vacuum Rabi splitting is seen when the interaction strength exceeds the dissipative processes of the coupled system. In order to increase the probability of a spectral matching between cavity modes and quantum dot transitions, a technique for condensing an inert gas onto a sample is used. This can lead to a spectral tuning of up to 4 nm of the cavity mode with minimal change in the cavity quality factor while maintaining cryogenic temperatures down to 4 K. The effect of a large density of quantum dots within a quantum dot photonic crystal slab nanocavity is also addressed. Gain and absorption effects are found to occur, changing the cavity emission linewidth from that of its intrinsic value, as well as lasing with a low number of quantum dots and with high spontaneous emission coupling factors. Additionally, methods for improving the quality factor of GaAs photonic crystal cavities and better understanding different loss mechanisms are discussed. In the individual studies, the site-selective growth of InAs quantum dots on pre-structured GaAs wafers is shown as a promising method for the eventual deterministic fabrication of photonic crystal cavities to single quantum dots. An in-situ annealing step is used to reduce quantum dot density, helping ensure that dots are not grown in unwanted locations. Given silicon's potential for achieving higher quality factors than its GaAs counterpart, a study of 1D passive silicon photonic crystal nanobeam cavities is carried out. Transmission through a coupled microfiber is used to measure quality factors of the cavities and compared with that of a crossed polarized resonant scattering measurement.
Download or read book Towards On demand Generation of Entangled Photons with Quantum Dots written by Arash Ahmadi and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The biexciton-exciton cascade in quantum dots (QDs) yields entangled photon pairs, and recent developments in engineering photonic structures around the dot for efficient light extraction and proper control of the fine-structure splitting, has led to significant breakthroughs in achieving an ideal entangled photon source -- exhibiting properties such as high extraction efficiency, low multi-photon emission and high entanglement fidelity. This thesis presents our development in enhancing the performance of entangled photon generation of QDs towards near-unity efficiency and fidelity. We study InAsP quantum dots in photonic nanowires for efficient light extraction and to reveal the effect of a quantum dot with high nuclear spin on the entanglement fidelity. Revealing the ultimate limit of entanglement in QDs is still a challenge, and it is generally believed that a sample made of atoms possessing high nuclear spins exhibits limited entanglement due to the dephasing caused by spin-spin interactions. Moreover, it is assumed that the fine-structure splitting of QDs degrades the entanglement fidelity, as it introduces a which-path information in the biexciton-exciton cascade. We have performed two-photon state tomography on InAsP QDs in InP nanowires, comprising of nuclear spin 9/2, and have realized that such a source is capable of generating entangled photon pairs with negligible dephasing during the emission lifetime, with a peak concurrence C = 77% and a count-weighted average concurrence 62%. This result was obtained by comparing the outcome of our measurements with a theoretical model that assumes no dephasing, however, takes into account the details of the detection system, i.e., dark-count rates and timing resolution, as well as, specific features of the QD, e.g., emission lifetime, fine-structure splitting, multi-photon emission probability, etc. Proper engineering of tapered nanowires allows for extraction of the emitted photons with high efficiency, which makes it possible to perform a complete two-photon state tomography and monitoring the evolution of the exciton state, as well as, the entanglement fidelity of the photon-pair, during the emission lifetime. This enabled us to reveal the effect of an imperfect detection system, as well as, multi-photon emission in recording low values for entanglement fidelity. Moreover, our calculations show that proper analysis of the time-energy uncertainty relation provides the necessary means to measure a high entanglement fidelity even in the presence of fine-structure splitting; since, a detection system with high timing resolution can overlook the which-path information, as the uncertainty in measuring the energy of the photons will be larger than the fine-structure splitting. Therefore, realizing near-unity entanglement fidelity using QDs is merely a technical challenge, i.e., resonant excitation of the QD, in order to suppress multi-photon emission, and use of a detection system with low timing jitter and dark-count rates. As a next step to achieve this goal, we have performed the resonant two-photon excitation scheme for the first time on a QD in a photonic nanowire, which resulted in an enhancement of the performance of our source. We managed to improve the single-photon purity of the source, g^(2)(0), by two orders of magnitude; moreover, analysis of the emission spectrum reveals that this scheme increases the pair-production efficiency to values above 93% for the biexciton-exciton cascade. Taking the efficiency of our experimental setup into consideration, the results indicate an approximately eight-fold enhancement of the pair-extraction efficiency as compared to the quasi-resonant excitation scheme (12.55% vs. 1.6%). Based on these results, two-photon state tomography on our source, under resonant two-photon excitation and performed by a detection system with high timing resolution and low dark-count rates, yields near-unity entanglement fidelity. By considering the enhancement in pair-extraction efficiency that we obtained, QDs in photonic nanowires can surpass the performance of spontaneous parametric down conversion sources in terms of entanglement fidelity and pair-extraction efficiency. Even though we have shown a finite fine-structure splitting does not degrade the entanglement fidelity in QDs, for various application in quantum information removing the fine-structure splitting is beneficial. Therefore, we have proposed a universal all-optical approach for removing the fine-structure splitting. In this scheme, the energy of the photons are shifted by using a pair of quarter-wave plates and fast-rotating half-wave plates after they have been emitted; and as a result, the energy difference between the two decay paths in the biexciton-exciton cascade is erased. This method is applicable to any QD source and can be easily implemented using the currently available technology; moreover, no further sample processing will be required in order to achieve zero fine-structure splitting.
Download or read book Quantum Dots for Quantum Information Technologies written by Peter Michler and published by Springer. This book was released on 2017-06-01 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the most recent developments in quantum dot spin physics and the generation of deterministic superior non-classical light states with quantum dots. In particular, it addresses single quantum dot spin manipulation, spin-photon entanglement and the generation of single-photon and entangled photon pair states with nearly ideal properties. The role of semiconductor microcavities, nanophotonic interfaces as well as quantum photonic integrated circuits is emphasized. The latest theoretical and experimental studies of phonon-dressed light matter interaction, single-dot lasing and resonance fluorescence in QD cavity systems are also provided. The book is written by the leading experts in the field.
Download or read book Quantum Dots written by Alexander Tartakovskii and published by Cambridge University Press. This book was released on 2012-07-19 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of cutting-edge solid state research, focusing on quantum dot nanostructures, for graduate students and researchers.
Download or read book Network Integration of a Quantum Dot Entangled Photon pair Source written by Ziheng Xiang and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Toward On Demand Generation of Entangled Photon Pairs with a Quantum Dot written by Arash Ahmadi and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The generation of on-demand, optimally entangled photon pairs remains one of the most formidable challenges in the quantum optics and quantum information community. Despite the fact that recent developments in this area have opened new doors leading toward the realization of sources exhibiting either high brightness or near-unity entanglement fidelity, the challenges to achieve both together persist. Here, we will provide a historical review on the development of quantum dots (QDs) for entangled photon generation, with a focus on nanowire QDs, and address the latest research performed on nanowire QDs, including measuring entanglement fidelity, light-extraction efficiency, dephasing mechanisms, and the detrimental effects of detection systems on the measured values of entanglement fidelity. Additionally, we will discuss results recently observed pertaining to resonant excitation of a nanowire QD, revealing the potential of such sources to outperform spontaneous parametric down-conversion (SPDC) sources, providing a viable solution to the current challenges in quantum optics and quantum information.
Download or read book Quantum Nano Photonics written by Baldassare Di Bartolo and published by Springer. This book was released on 2018-09-19 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together more closely researchers working in the two fields of quantum optics and nano-optics and provides a general overview of the main topics of interest in applied and fundamental research. The contributions cover, for example, single-photon emitters and emitters of entangled photon pairs based on epitaxially grown semiconductor quantum dots, nitrogen vacancy centers in diamond as single-photon emitters, coupled quantum bits based on trapped ions, integrated waveguide superconducting nanowire single-photon detectors, quantum nano-plasmonics, nanosensing, quantum aspects of biophotonics and quantum metamaterials. The articles span the bridge from pedagogical introductions on the fundamental principles to the current state-of-the-art, and are authored by pioneers and leaders in the field. Numerical simulations are presented as a powerful tool to gain insight into the physical behavior of nanophotonic systems and provide a critical complement to experimental investigations and design of devices.
Download or read book Solid State Cavity Quantum Electrodynamics with Quantum Dots Coupled to Photonic Crystal Cavities written by Arka Majumdar and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum dots (QDs) coupled to optical cavities constitute a scalable, robust, on-chip, semiconductor platform for probing fundamental cavity quantum electrodynamics. Very strong interaction between light and matter can be achieved in this system as a result of the eld localization inside sub-cubic wavelength volumes leading to vacuum Rabi frequencies in the range of 10s of GHz. Such strong light-matter interaction produces an optical nonlinearity that is present even at single-photon level and is tunable at a very fast time-scale. This enables one to go beyond fundamental cavity quantum electrodynamics (CQED) studies and to employ such e ects for building practical information processing devices. My PhD work has focused on both fundamental physics of the coupled QD-nanocavity system, as well as on several proof-of-principle devices for low-power optical information processing based on this platform. We have demonstrated the e ects of photon blockade and photon-induced tunneling, which con rm the quantum nature of the coupled dot-cavity system. Using these e ects and the photon correlation measurements of light transmitted through the dot-cavity system, we identify the rst and second order energy manifolds of the Jaynes-Cummings ladder describing the strong coupling between the quantum dot and the cavity eld, and propose a new way to generate multi-Fock states with high purity. In addition, the interaction of the quantum dot with its semiconductor environment gives rise to novel phenomena unique to a solid state cavity QED system, namely phonon-mediated o -resonant dot-cavity coupling. We have employed this effect to perform cavity-assisted resonant quantum dot spectroscopy, which allows us to resolve frequency features far below the limit of a conventional spectrometer. Finally, the applications of such a coupled dot-cavity system in optical information processing including ultrafast, low power all-optical switching and electro-optic modulation are explored. With the light-matter interactions controlled at the most fundamental level, the nano-photonic devices we implemented on this platform operate at extremely low control powers and could achieve switching speeds potentially exceeding 10 GHz.
Download or read book Cavity enhanced Photon Photon Interactions With Bright Quantum Dot Sources written by Valérian Giesz and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the pursuit of developing a quantum information network, photons appear to be the most convenient carriers to interconnect distant ports. The need to get on-demand single photons that is one and only one photon, with a high reliability, is the main driving force for the development of bright solid-state sources. One important parameter is the brightness defined as the probability that one collected pulse contains a single photon. For some applications like quantum information processing or long distance quantum communications, the emitted single photons must be also indistinguishable, so that can make use of their quantum interference to implement effective photon-photon interactions. To reach the ideal source of single and indistinguishable photons, different systems are explored : defects in diamond (NV centers), trapped atoms or ions, single molecules or semiconductor quantum dots.By coupling a semiconductor quantum dot to an optical cavity, the spontaneous emission of the emitter can be modified to obtain bright single-photon sources. An innovative technique was developed by Pr. Pascale Senellart and her team at the Laboratory of Photonics and Nanostructures (LPN) from CNRS that allows making such sources in a very reproducible way.This work explores the performance of single quantum dot coupled to micropillars. Various techniques are used in order to increase the single photon purity and indistinguishability while keeping a high source brightness. First, the cavity was modified using an adiabatic architecture such that a strong acceleration of the spontaneous emission was implemented. Then, a technique to apply an electric bias on the micropillars has been developed. The combination of the electric bias with a resonant optical excitation of the quantum dot allows to generation purely indistinguishable photons with a high brightness.The results developed in this thesis open a vast field of novel applications in quantum technologies, from quantum cryptography, metrology to quantum imaging.
Download or read book Self Assembled Quantum Dots written by Zhiming M Wang and published by Springer Science & Business Media. This book was released on 2007-11-29 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multidisciplinary book provides up-to-date coverage of carrier and spin dynamics and energy transfer and structural interaction among nanostructures. Coverage also includes current device applications such as quantum dot lasers and detectors, as well as future applications to quantum information processing. The book will serve as a reference for anyone working with or planning to work with quantum dots.
Download or read book Single Quantum Dots written by Peter Michler and published by Springer Science & Business Media. This book was released on 2003-12-09 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special focus is given to the optical and electronic properties of single quantum dots due to their potential applications in devices operating with single electrons and/or single photons. This includes quantum dots in electric and magnetic fields, cavity-quantum electrodynamics, nonclassical light generation, and coherent optical control of excitons.
Download or read book The Physics of Quantum Information written by Dirk Bouwmeester and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading experts from "The Physics of Quantum Information" network, initiated by the European Commission, bring together the most recent results from this emerging area of quantum technology. Written in a consistent style as a research monograph, the book introduces quantum cryptography, quantum teleportation, and quantum computation, considering both theory and newest experiments. Both scientists working in the field and advanced students will find a rich source of information on this exciting new area.
Download or read book Single photon Devices and Applications written by Charles Santori and published by John Wiley & Sons. This book was released on 2010-11-01 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past ten years, on-demand single photon generation has been realized in numerous physical systems including neutral atoms, ions, molecules, semiconductor quantum dots, impurities and defects in solids, and superconductor circuits. The motivations for generation and detection of single photons are two-fold: basic and applied science. On the one hand, a single photon plays a central role in the experimental foundation of quantum mechanics and measurement theory. On the other hand, an efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Written by top authors from academia and industry, this is the only textbook focused on single-photon devices and thus fills the gap for a readily accessible update on the rapid progress in the field.
Download or read book Quantum Photonics Pioneering Advances and Emerging Applications written by Robert W. Boyd and published by Springer. This book was released on 2019-02-27 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together reviews by internationally renowed experts on quantum optics and photonics. It describes novel experiments at the limit of single photons, and presents advances in this emerging research area. It also includes reprints and historical descriptions of some of the first pioneering experiments at a single-photon level and nonlinear optics, performed before the inception of lasers and modern light detectors, often with the human eye serving as a single-photon detector. The book comprises 19 chapters, 10 of which describe modern quantum photonics results, including single-photon sources, direct measurement of the photon's spatial wave function, nonlinear interactions and non-classical light, nanophotonics for room-temperature single-photon sources, time-multiplexed methods for optical quantum information processing, the role of photon statistics in visual perception, light-by-light coherent control using metamaterials, nonlinear nanoplasmonics, nonlinear polarization optics, and ultrafast nonlinear optics in the mid-infrared.
Download or read book Recent Advances in Nanophotonics written by Mojtaba Kahrizi and published by BoD – Books on Demand. This book was released on 2020-11-26 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together several recent research articles in the field of nanophotonics. The editors have arranged the chapters in three main parts: quantum devices, photonic devices, and semiconductor devices. The chapters cover a wide variety of scopes in those areas including principles of plasmonic, SPR, LSPR and their applications, graphene-based nanophotonic devices, generation of entangled photon and quantum dots, perovskite solar cells, photo-detachment and photoionization of two-electrons systems, diffusion and intermixing of atoms in semiconductor crystals, lattice and molecular elastic and inelastic scattering including surface-enhanced Raman Scattering and their applications. It is our sincerest hope that science and engineering students and researchers could benefit from the new ideas and recent advances in the field that are covered in this book.
Download or read book Spins in Optically Active Quantum Dots written by Oliver Gywat and published by John Wiley & Sons. This book was released on 2010-02-01 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling a gap in the literature, this up-to-date introduction to the field provides an overview of current experimental techniques, basic theoretical concepts, and sample fabrication methods. Following an introduction, this monograph deals with optically active quantum dots and their integration into electro-optical devices, before looking at the theory of quantum confined states and quantum dots interacting with the radiation field. Final chapters cover spin-spin interaction in quantum dots as well as spin and charge states, showing how to use single spins for break-through quantum computation. A conclusion and outlook round off the volume. The result is a primer providing the essential basic knowledge necessary for young researchers entering the field, as well as semiconductor and theoretical physicists, PhD students in physics and material sciences, electrical engineers and materials scientists.
