Electromagnetic Trapping of Cold Atoms
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A Monte Carlo Simulation of Radiation Trapping in Electrodeless Gas Discharge Lamps
INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS D: APPLIED PHYSICS J. Phys. D: Appl. Phys. 37 (2004) 1780–1791 PII: S0022-3727(04)72696-0 A Monte Carlo simulation of radiation trapping in electrodeless gas discharge lamps Kapil Rajaraman1 and Mark J Kushner2,3 1 Department of Physics, University of Illinois, 1110 West Green St., Urbana, IL 61801, USA 2 Department of Electrical and Computer Engineering, University of Illinois, 1406 West Green St., Urbana, IL 61801, USA E-mail: [email protected] and [email protected] Received 29 November 2003 Published 16 June 2004 Online at stacks.iop.org/JPhysD/37/1780 doi:10.1088/0022-3727/37/13/009 Abstract Radiation trapping and transport are important to the power balance of low pressure non-equilibrium plasma lighting sources. This is particularly the case for radio frequency inductively coupled lamps having complex geometries and where control of radiation trapping is an important design consideration. To investigate these issues, a Monte Carlo radiation transport simulation was developed and integrated into a two-dimensional plasma dynamics model. Investigations were performed on the 254 nm 3 1 1 1 (6 P1–6 S0) and 185 nm (6 P1–6 S0) resonance radiation transitions from Hg in Ar/Hg electrodeless discharges. We found that analytically computed radiation trapping factors are less accurate when there is a non-uniform density of absorbers and emitters, as may occur in low pressure lamps, in our case due primarily to cataphoresis. For typical lamp conditions (hundreds of mTorr fill pressure of argon with the vapour pressure of Hg, a few megahertz driving frequency), the electromagnetic skin depth is much larger than the size of the vessel. -
Arxiv:2101.05398V2 [Quant-Ph] 12 Apr 2021 Lcdibtent Oma Tmcrsntr Hscon- Atoms This Additional Resonator
Single collective excitation of an atomic array trapped along a waveguide: a study of cooperative emission for different atomic chain configurations V.A. Pivovarov,1,2 L.V. Gerasimov,3, 2 J. Berroir,4 T. Ray,4 J. Laurat,4 A. Urvoy,4, ∗ and D.V. Kupriyanov3,2, † 1Physics Department, St.-Petersburg Academic University, Khlopina 8, 194021 St.-Petersburg, Russia 2Center for Advanced Studies, Peter the Great St-Petersburg Polytechnic University, 195251, St.-Petersburg, Russia 3Quantum Technologies Center, M.V. Lomonosov Moscow State University, Leninskiye Gory 1-35, 119991, Moscow, Russia 4Laboratoire Kastler Brossel, Sorbonne Universit´e, CNRS, ENS-Universit´ePSL, Coll`ege de France, 4 place Jussieu, 75005 Paris, France (Dated: April 14, 2021) Ordered atomic arrays trapped in the vicinity of nanoscale waveguides offer original light-matter interfaces, with applications to quantum information and quantum non-linear optics. Here, we study the decay dynamics of a single collective atomic excitation coupled to a waveguide in different configurations. The atoms are arranged as a linear array and only a segment of them is excited to a superradiant mode and emits light into the waveguide. Additional atomic chains placed on one or both sides play a passive role, either reflecting or absorbing this emission. We show that when varying the geometry, such a one-dimensional atomic system could be able to redirect the emitted light, to directionally reduce or enhance it, and in some cases to localize it in a cavity formed by the atomic mirrors bounding the system. I. INTRODUCTION figuration was theoretically explored in [18], with a single atom strategically placed inside a very short atomic res- Developing and harnessing hybrid platforms where neu- onator at one of its anti-nodes. -
Subradiance and Radiation Trapping in Cold Atoms
Subradiance and radiation trapping in cold atoms Patrizia Weiss1, Michelle O. Ara´ujo1;2, Robin Kaiser1 & William Guerin1 1 Universit´eC^oted'Azur, CNRS, Institut de Physique de Nice, France 2 CAPES Foundation, Ministry of Education of Brazil, Bras´ılia, DF 70040-020, Brazil E-mail: [email protected] February 2018 Abstract. We experimentally and numerically study the temporal dynamics of light scattered by large clouds of cold atoms after the exciting laser is switched off in the low intensity (linear optics) regime. Radiation trapping due to multiple scattering as well as subradiance lead to decay much slower than the single atom fluorescence decay. These two effects have already been observed separately, but the interplay between them remained to be understood. Here, we show that with well chosen parameters of the driving field, the two effects can occur at the same time, but follow different scaling behaviors. The subradiant decay is observed at late time and its rate is independent of the detuning, while the radiation trapping decay is observed at intermediate time and depends on the detuning through the optical depth of the sample. Numerical simulations based on random walk process and coupled-dipole equations support our interpretations. Our study clarifies the different interpretations and physical mechanisms at the origin of slow temporal dynamics of light in cold atoms. 1. Introduction Collective effects in light scattering by atomic ensembles have recently been the subject of intense research, both theoretically and experimentally [1, 2]. Even in the most simple situation, when the atomic system is driven by a low intensity laser (single- photon or linear-optics regime) and when the atomic cloud has a low density, various arXiv:1803.01646v1 [physics.atom-ph] 5 Mar 2018 phenomena can occur [3, 4, 5, 6]. -
Trapping and Manipulation of Laser-Cooled Metastable Argon Atoms at a Surface
Trapping and Manipulation of Laser-Cooled Metastable Argon Atoms at a Surface Dissertation zur Erlangung des akademischen Grades des Doktors der Naturwissenschaften (Dr. rer. nat.) an der Universität Konstanz Mathematisch-Naturwissenschaftliche Sektion Fachbereich Physik vorgelegt von Dominik Schneble Tag der mündlichen Prüfung: 20. Februar 2002 Referenten: Prof. Dr. T. Pfau Priv.-Doz. Dr. C. Bechinger Prof. Dr. G. Ganteför Abstract This thesis discusses experiments on the all-optical trapping and manipulation of laser- cooled metastable argon atoms at a surface. A magneto-optical surface trap (MOST) has been realized and studied. This novel hybrid trap combines a magneto-optical trap at a metallic surface with an optical evanescent-wave atom mirror. It allows laser-cooling and trapping of atoms in con- tact with an evanescent light field that separates the atomic cloud from the surface by a fraction of an optical wavelength. Based on this work, the continuous loading of a planar matter waveguide has been demonstrated. Loading into the waveguide, which was formed by the optical potential of a red-detuned standing light wave above the surface, was achieved via evanescent- field optical pumping from the MOST in sub-mdistancefromthesurface. In subsequent experiments, several light-induced atom-optical elements have been demonstrated in the planar waveguide geometry, including a continuous atom source, a switchable channel guide, an atom detector and an optical surface lattice. The source, the channel and the detector have been combined to form the first, albeit simple, atom- optical integrated circuit. Contents 1 Introduction 1 1.1 General Context ............................... 1 1.2 This Thesis .................................. 5 1.3 Outlook ................................... -
Momentum Transfer Using Chirped Standing Wave Fields: Bragg Scattering
Momentum transfer using chirped standing wave fields: Bragg scattering Vladimir S. Malinovsky and Paul R. Berman Michigan Center for Theoretical Physics & FOCUS Center, Department of Physics, University of Michigan, Ann Arbor, MI 48109-1120 We consider momentum transfer using frequency-chirped standing wave fields. Novel atom-beam splitter and mirror schemes based on Bragg scattering are presented. It is shown that a predeter- mined number of photon momenta can be transferred to the atoms in a single interaction zone. PACS numbers: 03.75.Dg, 32.80.-t, 42.50.Vk Atom optics has experienced rapid advances in recent ing the entire evolution of the atom-field interaction and years. Applications of atom optics to inertial sensing [1], spontaneous emission plays a negligible role. We use atom holography [2, 3] and certain schemes for quantum chirped pulses to produce efficient momentum transfer computing [4, 5] can benefit substantially from the abil- sequentially to states having momentum ±n2~k, where ity to manipulate atomic motion in a controllable way. k is the propagation vector of one of the fields and n is There are a number of theoretical and experimental stud- a positive integer. The chirp rate and pulse duration are ies devoted to this problem [6, 7, 8, 9]. used to control the final target state. This work is com- The underlying physical mechanism responsible for op- plementary to that involving the use of adiabatic rapid tical control of atomic motion is an exchange of momen- passage to accelerate atoms that are trapped in optical tum between the atoms and the fields. -
A Monte Carlo Simulation of Radiation Trapping in Electrodeless Gas Discharges Having Complex Geometries*
A MONTE CARLO SIMULATION OF RADIATION TRAPPING IN ELECTRODELESS GAS DISCHARGES HAVING COMPLEX GEOMETRIES* Kapil Rajaraman** and Mark J. Kushner*** **Department of Physics ***Department of Electrical and Computer Engineering University of Illinois Urbana, IL 61801 email: [email protected] [email protected] *Work supported by Osram-Sylvania and the NSF AGENDA · Radiation transport in low pressure plasmas · Overview of the Hybrid Plasma Equipment Model · Description of Monte Carlo Transport model · Base case plasma properties · Dependence of radiation trapping factor on - Plasma geometry - Pressure - Gas temperature · Emission spectra · Conclusion __________________ University of Illinois Optical and Discharge Physics ICOPS01_2 ELECTRODELESS LAMPS AND TRAPPING · Electrodeless gas discharges are finding increasing use in lighting applications due to their increased lifetime. · Investigations are underway to increase the efficiency of these lamps, now @ 25% · Typical fluorescent lamps consist of Ar/Hg » 97/3. Resonance radiation 3 from Hg(6 P1) (254 nm) excites phosphors which generate visible light. 1 · Resonance radiation, produced by electron impact excitation of Hg (6 S0) 3 to Hg(6 P1), can be absorbed and reemitted many times prior to striking the phosphor. · The consequence of radiation trapping is to lengthen the effective lifetime of emission as viewed from outside the lamp. · Control of resonance radiation trapping is therefore important to the design of such lamps. __________________ University of Illinois Optical and Discharge Physics ICPOS01_3 PHYSICAL PROCESSES · The excited Hg and Ar levels have been treated as a single state. hv e e Hg e Hg* Hg+ hv e , Ar* , Ar e e Ar Ar* Ar+ e Ar* e · Ar is a buffer gas. -
Quantum Reflection from the Casimir-Polder Potential
THÈSE DE DOCTORAT DE L’UNIVERSITÉ PIERRE ET MARIE CURIE Spécialité : Physique École doctorale : “Physique en Île-de-France” réalisée au Laboratoire Kastler-Brossel présentée par Gabriel DUFOUR pour obtenir le grade de DOCTEUR DE L’UNIVERSITÉ PIERRE ET MARIE CURIE Sujet de la thèse : Réflexion quantique sur le potentiel de Casimir-Polder – Quantum reflection from the Casimir-Polder potential soutenue le 20 novembre 2015 devant le jury composé de M Andreas Buchleitner Rapporteur M David Guéry-Odelin Rapporteur Mme Marie-Christine Angonin Examinatrice M Olivier Dulieu Examinateur M Valery Nesvizhevsky Examinateur Mme Astrid Lambrecht Directrice de thèse i À la mémoire de mes grands-pères, Jean Dufour et Michel Durin ii Quand j’ai poussé la porte du Laboratoire Kastler Brossel en novembre 2011, je re- venais d’un mois de voyage à vélo sur les routes et chemins d’Italie. Astrid Lambrecht et Serge Reynaud m’ont convaincu de me lancer dans une nouvelle aventure, avec son lot d’ascensions ardues, de petites victoires, de problèmes techniques et de découvertes grisantes. Astrid et Serge m’ont accompagné sans relâche au cours du stage et de la thèse qui ont suivi. Je les remercie chaleureusement pour leur gentillesse et leur patience, leurs mots d’encouragement et les nombreuses discussions passionnantes que nous avons eues. Marie-Pascale Gorza, Romain Guérout, Manuel Donaire et Axel Maury ont été mes compagnons de route au sein de l’équipe “fluctuations quantiques et relativité”. Leurs conversations stimulantes et animées ont égayé bien des austères journées de travail. J’ai aussi partagé de très bons moments avec mes collègues et amis du laboratoire et d’au delà, que ce soit dans les courants d’air de la cantine, sous le soleil des arènes ou dans l’ambiance chaleureuse d’une cafétéria. -
Emission Cross Sections for Neutral Xenon Impacted by Xe+ and Xe2+
Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Dissertations, Master's Theses and Master's Reports - Open Reports 2006 Emission cross sections for neutral xenon impacted by Xe+ and Xe2+ Jason D. Sommerville Michigan Technological University Follow this and additional works at: https://digitalcommons.mtu.edu/etds Part of the Mechanical Engineering Commons Copyright 2006 Jason D. Sommerville Recommended Citation Sommerville, Jason D., "Emission cross sections for neutral xenon impacted by Xe+ and Xe2+", Master's Thesis, Michigan Technological University, 2006. https://doi.org/10.37099/mtu.dc.etds/412 Follow this and additional works at: https://digitalcommons.mtu.edu/etds Part of the Mechanical Engineering Commons Emission Cross Sections for Neutral Xenon Impacted by Xe+ and Xe2+ by Jason D. Sommerville A Thesis Submitted in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2006 Copyright c 2006 Jason D. Sommerville MICHIGAN TECHNOLOGICAL UNIVERSITY Department of Mechanical Engineering-Engineering Mechanics This thesis entitled Emission cross sections for Neutral Xenon Impacted by Xe+ and Xe2+ by Jason D. Sommerville is hereby accepted in partial fulfillment of the require- ments for the degree of Master of Science in Mechanical Engineering. Signed: Thesis Advisor: Dr. Lyon B. King Date Department Chair: Dr. William W. Predebon Date To my wife Renata for your support and flexibility while I live the life of a graduate student. You are my workmate, playmate, lifemate, and soulmate. Abstract Ion impact emission cross sections for eleven transitions from the 5p56p configuration to the 5p56s configuration of neutral xenon occur- ring in the spectral region between 700 nm and 1000 nm have been measured experimentally. -
EIT Cavity of D = 500 and Ωc = 2Γ Within 2 Μs
All-optical control of superradiance and matter waves using a dispersive cavity Shih-Wei Su,1 Zhen-Kai Lu,2 Nina Rohringer,3, 4, 5 Shih-Chuan Gou,1 and Wen-Te Liao3, 4, 5, 6, ∗ 1Department of Physics and Graduate Institute of Photonics, National Changhua University of Education, Changhua 50058 Taiwan 2Max Planck Institute for Quantum Optics, D-85748 Garching, Germany 3Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany 4Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany 5Center for Free-Electron Laser Science, 22761 Hamburg, Germany 6Department of Physics, National Central University, 32001 Taoyuan City, Taiwan (Dated: Version of October 1, 2018.) Cavity quantum electrodynamics (CQED) [1] plays an elegant role of studying strong coupling between light and matter. However, a non-mechanical, direct and dynamical control of the used mirrors is still unavailable. Here we theoretically investigate a novel type of dynamically controllable cavity composed of two atomic mir- rors. Based on the electromagnetically induced transparency (EIT) [2,3], the reflectance of atomic mirror is highly controllable through its dispersive properties by varying the intensity of applied coupling fields or the optical depth of atomic media. To demonstrate the uniqueness of the present cavity, we further show the pos- sibility of manipulating vacuum-induced diffraction of a binary Bose-Einstein condensate (BEC) [4,5] when loading it into a dispersive cavity and experiencing superradiant scatterings [6]. Our results may provide a novel all-optical element for atom optics [7] and shine new light on controlling light-matter interaction. For decades, CQED has served as an elegant model for a backward probe field with Rabi frequency Ω− [13], and vise demonstrating atom-light interaction and fundamental princi- versa. -
Julio Gea-Banaclochea 'Department of Physics, University of Arkansas, Fayett,Eville, Arkansas, 72701, USA
Geometric phase gate with a quantized driving field Shabnam Siddiquia arid Julio Gea-Banaclochea 'Department of Physics, University of Arkansas, Fayett,eville, Arkansas, 72701, USA ABSTRACT We have studied the performance of a geometric phase gate with a quantized driving field numerically, and developed an analytical approximation that yields some preliminary insight on the way the nl~hltbecomes entangled with the driving field. Keywords: Quantum computation, adiabatic quantum gates, geometric quantum gates 1. INTRODUCTION It was first suggested by Zanardi and ~asetti,'that the Berry phase (non-abelian holon~m~)~-~might in principle provide a novel way for implementing universal quantum computation. They showed that by encoding quantum information in one of the eigenspaces of a degenerate Harniltonian H one can in principle achieve the full quantum computational power by using holonomies only. It was then thought that since Berry's phase is a purely geometrical effect, it is resilient to certain errors and may provide a possibility for performing intrinsically fault-tolerant quantum gate operations. In a paper by Ekert et.al,5 a detailed theory behind the implementation of geometric computation was developed and an implementation of a conditional phase gate in NMR was shown by Jones et.al.6 This attracted the attention of the research community and various studies were performed to study the rob~stness~-'~of geometric gates and the implementation of these gates in other systenls such as ion-trap, solid state and Josephson qubits.lO-l4 In this paper we study an adiabatic geometric phase gate when the control system is treated as a two mode quantized coherent field. -
Coupled Dynamics of Atoms and Radiation Pressure Driven
Coupled dynamics of atoms and radiation pressure driven interferometers D. Meiser and P. Meystre Department of Physics, The University of Arizona, 1118 E. 4th Street, Tucson, AZ 85721 We consider the motion of the end mirror of a cavity in whose standing wave mode pattern atoms are trapped. The atoms and the light field strongly couple to each other because the atoms form a distributed Bragg mirror with a reflectivity that can be fairly high. We analyze how the dipole potential in which the atoms move is modified due to this backaction of the atoms. We show that the position of the atoms can become bistable. These results are of a more general nature and can be applied to any situation where atoms are trapped in an optical lattice inside a cavity and where the backaction of the atoms on the light field cannot be neglected. We analyze the dynamics of the coupled system in the adiabatic limit where the light field adjusts to the position of the atoms and the light field instantaneously and where the atoms move much faster than the mirror. We calculate the side band spectrum of the light transmitted through the cavity and show that these spectra can be used to detect the coupled motion of the atoms and the mirror. I. INTRODUCTION R1,T1 R2,T2 atoms In recent years the coupling of the light field inside an optical resonator to the mechanical motion of the end Pin mirrors [1, 2, 3] has received renewed attention due to several developments. The improved capabilities to mi- 0 L L+ξ cromachine sub-micrometer sized mechanical structures with well defined mechanical and optical properties en- Figure 1: (Color online) Schematic of atoms in a cavity with ables the creation of moveable mirrors with small damp- a moveable mirror. -
Efficient Photon Recycling and Radiation Trapping in Cesium Lead
Letter Cite This: ACS Energy Lett. 2018, 3, 1492−1498 Efficient Photon Recycling and Radiation Trapping in Cesium Lead Halide Perovskite Waveguides † ‡ § § † † ‡ † ‡ Ibrahim Dursun, , Yangzi Zheng, Tianle Guo, Michele De Bastiani, Bekir Turedi, , Lutfan Sinatra, , ∥ ⊥ † ‡ ⊥ Md Azimul Haque, Bin Sun, Ayan A. Zhumekenov, , Makhsud I. Saidaminov, ⊥ ⊥ ∥ ○ § F. Pelayo García de Arquer, Edward H. Sargent, Tom Wu, , Yuri N. Gartstein, † ‡ † § Osman M. Bakr, , Omar F. Mohammed,*, and Anton V. Malko*, † KAUST Solar Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia ‡ KAUST Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia § Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080, United States ∥ Materials Science and Engineering, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia ⊥ Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3G4, Canada ○ School of Materials Science and Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia *S Supporting Information ABSTRACT: Cesium lead halide perovskite materials have attracted considerable attention for potential applications in lasers, light-emitting diodes, and photo- detectors. Here, we provide the experimental and theoretical evidence for photon recycling in CsPbBr3 perovskite microwires. Using two-photon excitation, we recorded photoluminescence (PL) lifetimes and emission spectra as a function of the lateral distance between PL excitation and collection positions along the microwire, with separations exceeding 100 μm. At longer separations, the PL spectrum develops a red-shifted emission peak accompanied by an appearance of well-resolved rise times in the PL kinetics.