DOCSLIB.ORG

Attosecond Analysis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Attosecond Analysis INTERVIEW | TECHNOLOGY FOCUS Attosecond analysis Attosecond spectroscopy promises real-time observation of the motion of electrons inside atoms. Nadya Anscombe talks to Ferenc Krausz from the Max-Planck Institute of Quantum Optics and the Ludwig-Maximilians-University of Munich in Germany about the technology. Why is attosecond off with the electric field of light. To advance spectroscopy important? electronics to its ultimate limits we will have If you want to capture a fast-moving object, to draw on attosecond technology. you need a fast shutter speed on your camera. Until recently, no experimental In spectroscopy, ultrashort light pulses act as technique existed that can directly probe that shutter and can take pictures of ultrafast electron–electron interactions in matter on microscopic dynamics. The development of the atomic scale. The accurate theoretical femtosecond pulses allowed the motion of description of these interactions and resultant atoms in molecules to be recorded and led to dynamics becomes very difficult for an the birth of femtochemistry. Now, attosecond increasing number of electrons. Even for pulses are required to capture the atomic- systems with just two electrons, no accurate scale motion of electrons in atoms, molecules ab initio calculations exist for the dynamical or solids. Unlike conventional techniques, behaviour. Attosecond spectroscopy can, for such as X-ray crystallography, attosecond the first time, offer a method of investigating IENNA spectroscopy gives real-time, direct, dynamic V these interactions experimentally and help information about the motion of electrons. OF Y theorists to develop simplified but reasonably Indirect ways of accessing such dynamics, t accurate models for describing multi-electron such as frequency-domain measurements, systems for addressing realistic situations. work in simple situations (such as in the case There are so many applications for of quantum transitions between well isolated this technology that no one group can states), but if there is interference as a result UNIVERSI TECHNICAL investigate them all. That is why it is of the many possible pathways or if many important that many groups around the quantum states are involved, the data can be Ferenc Krausz, one of the pioneers of attosecond science. world are developing attosecond technology, hard to decipher. Attosecond spectroscopy and I am pleased to see that research in the is the only way of getting real-time access field is proliferating rapidly. to dynamics occurring on the electronic What are the applications for timescale, that is, to processes clocked in the attosecond spectroscopy? What needs to be done before atomic unit of time of 24 as. Because attosecond spectroscopy can be the technology becomes used to look at the dynamic behaviour of commercially available? What can be achieved with the electrons, the list of applications is endless. More than half of an attosecond technology today? For example, in life sciences attosecond measurement system is already The shortest pulses demonstrated so far spectroscopy may ultimately create ways commercially available. Few-cycle phase- have a duration of 80 as. These pulses, of understanding the microscopic origins controlled near-infrared laser systems, thanks to the order-of-magnitude increase of how a disease, such as cancer, emerges which serve as a driver of the attosecond in their photon flux as compared with their and develops at the most fundamental pulses, are available off-the-shelf. The rest predecessors, enable measurements with a level: in terms of the motion of electrons. is simple and complicated at the same time. dramatically improved signal-to-noise ratio, In biology, structure determines function The attosecond source, a gas jet, is extremely offering a temporal resolution close to the or malfunction. Although a change in simple, whereas the part needed for atomic unit of time. Attosecond spectroscopy structure can take a long time, the initial performing the attosecond measurements is was previously used to study isolated atoms event that triggered the change is always more complex. The design of a measurement in the gas phase, but the technique has now an electronic motion. To understand why system very much depends on what you been extended to observe electron motion in a molecule decides to change its structure want to investigate. There are no major condensed-matter systems and on surfaces or composition, you have to understand hurdles to be overcome with the technology in real time. Attosecond photoemission what happens at the instant when that itself: it is ready to be used. However, the spectroscopy presents a clear path towards change begins. Attosecond spectroscopy can equipment used today is complex and it is ultimately uncovering the intermediate observe these events in real time. important to make it reliable and easy to use, processes involved in the ejection of a Advancement of modern electronics as researchers do not want to go through photoelectron from condensed matter. This towards its ultimate frontier — the atomic years of training before they can use the is a basic process analysed by Einstein more scale, in both space and time — means that technology to do important research. than a hundred years ago, but with many one day we will want to be able to make important details remaining hidden to the electronic circuits from atomic structures and Nadya Anscombe is a freelance science and present day. to switch currents in these circuits on and technology journalist based in the UK. 548 nature photonics | VOL 2 | SEPTEMBER 2008 | www.nature.com/naturephotonics © 2008 Macmillan Publishers Limited. All rights reserved. .
Load more

Recommended publications
  • Arxiv:1912.00017V1 [Physics.Atom-Ph] 29 Nov 2019
    Theoretical Atto-nano Physics Marcelo F. Ciappina1 and Maciej Lewenstein2, 3 1Institute of Physics of the ASCR, ELI-Beamlines, Na Slovance 2, 182 21 Prague, Czech Republic 2ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain 3ICREA - Instituci´oCatalana de Recerca i Estudis Avan¸cats,Lluis Companys 23, 08010 Barcelona, Spain (Dated: December 3, 2019) Two emerging areas of research, attosecond and nanoscale physics, have recently started to merge. Attosecond physics deals with phenomena occurring when ultrashort laser pulses, with duration on the femto- and sub-femtosecond time scales, interact with atoms, molecules or solids. The laser- induced electron dynamics occurs natively on a timescale down to a few hundred or even tens of attoseconds (1 attosecond=1 as=10−18 s), which is of the order of the optical field cycle. For com- parison, the revolution of an electron on a 1s orbital of a hydrogen atom is ∼ 152 as. On the other hand, the second topic involves the manipulation and engineering of mesoscopic systems, such as solids, metals and dielectrics, with nanometric precision. Although nano-engineering is a vast and well-established research field on its own, the combination with intense laser physics is relatively recent. We present a comprehensive theoretical overview of the tools to tackle and understand the physics that takes place when short and intense laser pulses interact with nanosystems, such as metallic and dielectric nanostructures. In particular we elucidate how the spatially inhomogeneous laser induced fields at a nanometer scale modify the laser-driven electron dynamics.
    [Show full text]
  • Atomic Clocks, 14–19, 89–94 Attosecond Laser Pulses, 55–57
    Index high-order harmonic generation, A 258–261 in strong laser fields, 238–243 Atomic clocks, 14–19, 89–94 in weak field regime, 274-277 Attosecond laser pulses, 55–57 metal-ligand charge-transfer, 253–254 organic chemical conversion, C 249–251 pulse shaping, 269–274 CARS microscopy with ultrashort quantum ladder climbing, 285–287 pulses, 24–25 simple shaped pulses, 235–238 Chirped-pulse amplification, 54–55 Tannor-Kosloff-Rice scheme, phase preservation in, 54–5 232–235 Chirped pulses, 271, 274–277, 235–238 via many-parameter control in liquid Coherent control, 225–266, 267–304, phase, 252–255 atoms and dimers in gas phase, Coherent transients, 274–285 228–243 bond-selective photochemistry, 248–249 D closed-loop pulse shaping, 244–246 coherent coupling, 238–243 Dielectric breakdown, 305–329 molecular electronic states, in oxide thin films, 318 238–241 phenomenological model of, 316 atomic electronic states, retrieval of dielectric constant, 322 241–243 Difference frequency generation, 123 coherent transients, 274–285 Dynamics, 146–148, 150, 167–196, control of electron motion, 255–261 187–224 control of photo-isomerization, of electronic states, 146–148 254–255 of excitonic states, 150 control of two-photon transitions, hydrogen bond dynamics, 167–196 285-287 molecular dynamics, 187–196 332 Femtosecond Laser Spectroscopy Femtosecond optical frequency combs, E 1–8, 12–21, 55–57, 87–108, 109–112, 120–128 Exciton-vibration interaction, 153–158 absolute phase control of, 55–57 dynamic intensity borrowing, attosecond pulses, 55–57 156–158 carrier-envelope offset frequency, Franck-Condon type, 159 3, 121 Herzberg-Teller type, 159–160 carrier envelope phase, 2, 121 interactions, 14–19 mid-infrared, 19-21, 120–127 F molecular spectroscopy with, 12–14 Femtochemistry, 198, 226 optical frequency standards, 14–19 Femtosecond lasers, 1–27 optical atomic clocks, 14–19, external optical cavities, 21–25 89–94 high resolution spectroscopy with, Femtosecond photon echoes.
    [Show full text]
  • Attosecond Science on the East Coast
    Attosecond Science on the East Coast Luca Argenti, Zenghu Chang, Michael Chini, Madhab Neupane, Mihai Vaida, and Li Fang Department of Physics & CREOL University of Central Florida The steady progress experienced by extreme non-linear optics and pulsed laser technology during the last decade of the XX century led to a transformative backthrough: the generation, in 2001, of the first attosecond extreme ultraviolet pulse. This was a revolutionary achievement, as the attosecond is the natural timescale of electronic motion in matter. The advent of attosecond pulses, therefore, opened the way to the time-resolved study of correlated electron dynamics in atoms, molecules, surfaces, and solids, to the coherent control of charge-transfer processes in chemical reactions and in nano-devices as well as, possibly, to ultrafast processing of quantum information. Attosecond research has been in a state of tumultuous growth ever since, giving rise to countless high-profile publications, the formation of a large international research community, and the appearance of new leading research hubs across the world. The University of Central Florida is one of them, establishing itself as the center of excellence for attosecond science on the US East Coast. The UCF Physics Department and CREOL host six internationally recognized leaders in attosecond science, Zenghu Chang, Michael Chini, Luca Argenti, Madhab Neupane, Mihai Vaida, and Li Fang (listed in the order they joined UCF), covering virtually all branches of this discipline, with topics ranging from theoretical photoelectron spectroscopy, to high-harmonic generation in gases and solids, the transient-absorption study of molecular core-holes decay, the time and angularly-resolved photoemission from topological insulators, heterogeneous catalysis control, and ultrafast nanoplasma physics.
    [Show full text]
  • Generation of Attosecond Light Pulses from Gas and Solid State Media
    hv photonics Review Generation of Attosecond Light Pulses from Gas and Solid State Media Stefanos Chatziathanasiou 1, Subhendu Kahaly 2, Emmanouil Skantzakis 1, Giuseppe Sansone 2,3,4, Rodrigo Lopez-Martens 2,5, Stefan Haessler 5, Katalin Varju 2,6, George D. Tsakiris 7, Dimitris Charalambidis 1,2 and Paraskevas Tzallas 1,2,* 1 Foundation for Research and Technology—Hellas, Institute of Electronic Structure & Laser, PO Box 1527, GR71110 Heraklion (Crete), Greece; [email protected] (S.C.); [email protected] (E.S.); [email protected] (D.C.) 2 ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, 6720 Szeged, Hungary; [email protected] (S.K.); [email protected] (G.S.); [email protected] (R.L.-M.); [email protected] (K.V.) 3 Physikalisches Institut der Albert-Ludwigs-Universität, Freiburg, Stefan-Meier-Str. 19, 79104 Freiburg, Germany 4 Dipartimento di Fisica Politecnico, Piazza Leonardo da Vinci 32, 20133 Milano, Italy 5 Laboratoire d’Optique Appliquée, ENSTA-ParisTech, Ecole Polytechnique, CNRS UMR 7639, Université Paris-Saclay, 91761 Palaiseau CEDEX, France; [email protected] 6 Department of Optics and Quantum Electronics, University of Szeged, Dóm tér 9., 6720 Szeged, Hungary 7 Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany; [email protected] * Correspondence: [email protected] Received: 25 February 2017; Accepted: 27 March 2017; Published: 31 March 2017 Abstract: Real-time observation of ultrafast dynamics in the microcosm is a fundamental approach for understanding the internal evolution of physical, chemical and biological systems. Tools for tracing such dynamics are flashes of light with duration comparable to or shorter than the characteristic evolution times of the system under investigation.
    [Show full text]
  • Attosecond Streaking Spectroscopy of Atoms and Solids
    U. Thumm et al., in: Fundamentals of photonics and physics, D. L. Andrew (ed.), Chapter 13 (Wiley, New York 2015) Chapter x Attosecond Physics: Attosecond Streaking Spectroscopy of Atoms and Solids Uwe Thumm1, Qing Liao1, Elisabeth M. Bothschafter2,3, Frederik Süßmann2, Matthias F. Kling2,3, and Reinhard Kienberger2,4 1 J.R. Macdonald Laboratory, Physics Department, Kansas-State University, Manhattan, KS66506, USA 2 Max-Planck Institut für Quantenoptik, 85748 Garching, Germany 3 Physik Department, Ludwig-Maximilians-Universität, 85748 Garching, Germany 4 Physik Department, Technische Universität München, 85748 Garching, Germany 1. Introduction Irradiation of atoms and surfaces with ultrashort pulses of electromagnetic radiation leads to photoelectron emission if the incident light pulse has a short enough wavelength or has sufficient intensity (or both)1,2. For pulse intensities sufficiently low to prevent multiphoton absorption, photoemission occurs provided that the photon energy is larger than the photoelectron’s binding energy prior to photoabsorption, ħ휔 > 퐼푃. Photoelectron emission from metal surfaces was first analyzed by Albert Einstein in terms of light quanta, which we now call photons, and is commonly known as the photoelectric effect3. Even though the photoelectric effect can be elegantly interpreted within the corpuscular description of light, it can be equally well described if the incident radiation is represented as a classical electromagnetic wave4,5. With the emergence of lasers able to generate very intense light, it was soon shown that at sufficiently high intensities (routinely provided by modern laser systems) the condition ħω < 퐼푃 no longer precludes photoemission. Instead, the absorption of two or more photons can lead to photoemission, where 6 a single photon would fail to provide the ionization energy Ip .
    [Show full text]
  • Attosecond Time-Resolved Photoelectron Holography
    ARTICLE DOI: 10.1038/s41467-018-05185-6 OPEN Attosecond time-resolved photoelectron holography G. Porat1,2, G. Alon2, S. Rozen2, O. Pedatzur2, M. Krüger 2, D. Azoury2, A. Natan 3, G. Orenstein2, B.D. Bruner2, M.J.J. Vrakking4 & N. Dudovich2 Ultrafast strong-field physics provides insight into quantum phenomena that evolve on an attosecond time scale, the most fundamental of which is quantum tunneling. The tunneling 1234567890():,; process initiates a range of strong field phenomena such as high harmonic generation (HHG), laser-induced electron diffraction, double ionization and photoelectron holography—all evolving during a fraction of the optical cycle. Here we apply attosecond photoelectron holography as a method to resolve the temporal properties of the tunneling process. Adding a weak second harmonic (SH) field to a strong fundamental laser field enables us to recon- struct the ionization times of photoelectrons that play a role in the formation of a photo- electron hologram with attosecond precision. We decouple the contributions of the two arms of the hologram and resolve the subtle differences in their ionization times, separated by only a few tens of attoseconds. 1 JILA, National Institute of Standards and Technology and University of Colorado-Boulder, Boulder, CO 80309-0440, USA. 2 Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel. 3 Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA. 4 Max-Born-Institut, Max Born Strasse 2A, Berlin 12489, Germany. These authors contributed equally: G. Porat, G. Alon. Correspondence and requests for materials should be addressed to N.D.
    [Show full text]
  • Attosecond Light Pulses and Attosecond Electron Dynamics Probed Using Angle-Resolved Photoelectron Spectroscopy
    Attosecond Light Pulses and Attosecond Electron Dynamics Probed using Angle-Resolved Photoelectron Spectroscopy Cong Chen B.S., Nanjing University, 2010 M.S., University of Colorado Boulder, 2013 A thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirement for the degree of Doctor of Philosophy Department of Physics 2017 This thesis entitled: Attosecond Light Pulses and Attosecond Electron Dynamics Probed using Angle-Resolved Photoelectron Spectroscopy written by Cong Chen has been approved for the Department of Physics Prof. Margaret M. Murnane Prof. Henry C. Kapteyn Date The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. iii Chen, Cong (Ph.D., Physics) Attosecond Light Pulses and Attosecond Electron Dynamics Probed using Angle-Resolved Photoelectron Spectroscopy Thesis directed by Prof. Margaret M. Murnane Recent advances in the generation and control of attosecond light pulses have opened up new opportunities for the real-time observation of sub-femtosecond (1 fs = 10-15 s) electron dynamics in gases and solids. Combining attosecond light pulses with angle-resolved photoelectron spectroscopy (atto-ARPES) provides a powerful new technique to study the influence of material band structure on attosecond electron dynamics in materials. Electron dynamics that are only now accessible include the lifetime of far-above-bandgap excited electronic states, as well as fundamental electron interactions such as scattering and screening. In addition, the same atto-ARPES technique can also be used to measure the temporal structure of complex coherent light fields.
    [Show full text]
  • Femtosecond and Attosecond Spectroscopy in the XUV Regime Arvinder S
    IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 18, NO. 1, JANUARY/FEBRUARY 2012 351 Femtosecond and Attosecond Spectroscopy in the XUV Regime Arvinder S. Sandhu and Xiao-Min Tong (Invited Paper) Abstract—Attosecond-duration, fully coherent, extreme- [7], [8]. Time-resolved experiments with these laser-generated ultraviolet (XUV) photon bursts obtained through laser XUV pulses provide new insights into the electronic processes high-harmonic generation have opened up new possibilities in the in atoms, molecules, and surfaces [1]–[6], [9]–[15]. study of atomic and molecular dynamics. We discuss experiments elucidating some of the interesting energy redistribution mecha- Strictly speaking, apart from attosecond XUV pulses, the im- nisms that follow the interaction of a high-energy photon with a plementation of ultrafast XUV spectroscopy also requires pre- molecule. The crucial role of synchronized, strong-field, near-IR cisely synchronized strong field IR laser pulses. In fact, many laser pulses in XUV pump–probe spectroscopy is highlighted. We new experimental possibilities have emerged from this marriage demonstrate that near-IR pulses can in fact be used to modify between conventional strong-field (IR) and weak-field (XUV) the atomic structure and control the electronic dynamics on attosecond timescales. Our measurements show that the Gouy spectroscopic techniques. We refer to this entire class of exper- phase slip in the interaction region plays a significant role in these iments as ultrafast XUV+IR spectroscopy. attosecond experiments. We perform precision measurement of In the framework of XUV+IR spectroscopy, we will focus interferences between strong field-induced Floquet channels to on the developments along two main directions.
    [Show full text]
  • Attosecond Physics at the Nanoscale
    Home Search Collections Journals About Contact us My IOPscience Attosecond physics at the nanoscale This content has been downloaded from IOPscience. Please scroll down to see the full text. 2017 Rep. Prog. Phys. 80 054401 (http://iopscience.iop.org/0034-4885/80/5/054401) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 130.183.90.175 This content was downloaded on 09/05/2017 at 14:52 Please note that terms and conditions apply. You may also be interested in: High energy photoelectron emission from gases using plasmonic enhanced near-fields M F Ciappina, T Shaaran, R Guichard et al. Advances in attosecond science Francesca Calegari, Giuseppe Sansone, Salvatore Stagira et al. Numerical simulation of attosecond nanoplasmonic streaking E Skopalová, D Y Lei, T Witting et al. The birth of attosecond physics and its coming of age Ferenc Krausz Isolated few-attosecond emission in a multi-cycle asymmetrically nonhomogeneous two-color laser field Chao Yu, Yunhui Wang, Xu Cao et al. Spatial shaping of intense femtosecond beams for the generation of high-energy attosecond pulses E Constant, A Dubrouil, O Hort et al. Attosecond imaging of XUV-induced atomic photoemission and Auger decay in strong laser fields S Zherebtsov, A Wirth, T Uphues et al. IOP Reports on Progress in Physics Reports on Progress in Physics Rep. Prog. Phys. Rep. Prog. Phys. 80 (2017) 054401 (50pp) https://doi.org/10.1088/1361-6633/aa574e 80 Report on Progress 2017 Attosecond physics at the nanoscale © 2017 IOP Publishing Ltd M F Ciappina1,2, J A Pérez-Hernández3, A S Landsman4, W A Okell1, RPPHAG S Zherebtsov1, B Förg1, J Schötz1, L Seiffert5, T Fennel5, T Shaaran6, T Zimmermann7,8, A Chacón9, R Guichard10, A Zaïr11, J W G Tisch11, 11 11 11 11 3 054401 J P Marangos , T Witting , A Braun , S A Maier , L Roso , M Krüger1,12,13, P Hommelhoff1,12,14, M F Kling1,15, F Krausz1,15 and M Lewenstein9,16 M F Ciappina et al 1 Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str.
    [Show full text]
  • Siunitx – a Comprehensive (Si) Units Package∗
    siunitx – A comprehensive (si) units package∗ Joseph Wright† Released 2021-09-22 Contents 1 Introduction 3 2 siunitx for the impatient 3 3 Using the siunitx package 4 3.1 Numbers . 4 3.2 Angles . 5 3.3 Units . 6 3.4 Complex numbers and quantities . 7 3.5 The unit macros . 8 3.6 Unit abbreviations . 10 3.7 Creating new macros . 14 3.8 Tabular material . 15 4 Package control options 17 4.1 The key–value control system . 17 4.2 Printing . 18 4.3 Parsing numbers . 20 4.4 Post-processing numbers . 22 4.5 Printing numbers . 25 4.6 Lists, products and ranges . 28 4.7 Complex numbers . 31 4.8 Angles . 32 4.9 Creating units . 34 4.10 Using units . 35 4.11 Quantities . 38 4.12 Tabular material . 39 4.13 Locale options . 49 4.14 Preamble-only options . 49 5 Upgrading from version 2 49 6 Unit changes made by BIPM 51 ∗This file describes v3.0.31, last revised 2021-09-22. †E-mail: [email protected] 1 7 Localisation 52 8 Compatibility with other packages 52 9 Hints for using siunitx 52 9.1 Adjusting \litre and \liter ........................ 52 9.2 Ensuring text or math output . 53 9.3 Expanding content in tables . 53 9.4 Using siunitx with datatool .......................... 54 9.5 Using units in section headings and bookmarks . 55 9.6 A left-aligned column visually centred under a heading . 56 9.7 Regression tables . 57 9.8 Maximising performance . 58 9.9 Special considerations for the \kWh unit .
    [Show full text]
  • Download 01 Introduction -The Nature of Science and Physics.Pdf
    CHAPTER 1 Introduction: The Nature of Science and Physics Figure 1.1 Galaxies are as immense as atoms are small. Yet the same laws of physics describe both, and all the rest of nature—an indication of the underlying unity in the universe. The laws of physics are surprisingly few in number, implying an underlying simplicity to nature’s apparent complexity. (credit: NASA, JPL-Caltech, P. Barmby, Harvard- Smithsonian Center for Astrophysics) Chapter Outline 1.1 Physics: An Introduction • Explain the difference between a principle and a law. • Explain the difference between a model and a theory. 1.2 Physical Quantities and Units • Perform unit conversions both in the SI and English units. • Explain the most common prefixes in the SI units and be able to write them in scientific notation. 1.3 Accuracy, Precision, and Significant Figures • Determine the appropriate number of significant figures in both addition and subtraction, as well as multiplication and division calculations. • Calculate the percent uncertainty of a measurement. 1.4 Approximation • Make reasonable approximations based on given data. INTRODUCTION TO SCIENCE AND THE REALM OF PHYSICS, PHYSICAL QUANTITIES, AND UNITS What is your first reaction when you hear the word “physics”? Did you imagine working through difficult equations or memorizing ormulasf that seem to have no real use in life outside the physics classroom? Many people come to the subject of physics with a bit of fear. But as you begin your exploration of this broad-ranging subject, you may soon come to realize that physics plays a much larger role in your life than you first thought, no matter oury life goals or career choice.
    [Show full text]
  • Attosecond Control of Ionization by Wave-Packet Interference
    PHYSICAL REVIEW LETTERS week ending PRL 99, 233001 (2007) 7 DECEMBER 2007 Attosecond Control of Ionization by Wave-Packet Interference P. Johnsson,1,* J. Mauritsson,1,2 T. Remetter,1 A. L’Huillier,1 and K. J. Schafer2 1Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden 2Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001, USA (Received 24 August 2007; published 7 December 2007) A train of attosecond pulses, synchronized to an infrared (IR) laser field, is used to create a series of electron wave packets (EWPs) that are below the ionization threshold in .helium. The ionization probability is found to strongly oscillate with the delay between the IR and attosecond fields twice per IR laser cycle. Calculations that reproduce the experimental results demonstrate that this ionization control results from interference between transiently bound EWPs created by different pulses in the train. In this way, we are able to observe, for the first time, attosecond wave-packet interference in a strongly driven atomic system. DOI: 10.1103/PhysRevLett.99.233001 PACS numbers: 32.80.Rm, 32.80.Qk, 42.65.Ky Attosecond pulses [1,2] can be used to initiate and probing quantum dynamics because it depends on the control electron dynamics on a sub-femtosecond time scale spatial and temporal behavior of the wave packets in the [3]. The first step in this process occurs when an atom confining potential. The modulation in the total amount of absorbs an ultraviolet photon leading to the formation of an population excited out of the ground state results from the attosecond electron wave packet (EWP).
    [Show full text]