KITP Newsletter, Spring 2006
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CMC Citation for 2020 Micius Quantum Prize (Theory Portion)
The Sun rises in Albuquerque on December 10, 2020, as the Prize is announced in Beijing. CMC citation for 2020 Micius Quantum Prize (theory portion) For foundational work on quantum metrology and quantum information theory, especially for elucidating the fundamental noise in interferometers and its suppression with the use of squeezed states. CMC remarks at the press conference announcing award of the Prize First, thanks to the Micius Foundation for awarding me this prestigious, international research prize. The prize is aptly named for the ancient Chinese philosopher Micius, whose moral teachings emphasized introspection, self-reflection, and authenticity, all values that I hold dear, and who taught that all people are equal and that innovation is as valuable as tradition. Second, thanks to the Selection Committee. That this group of outstanding scientists thought that my scientific contributions are worthy of recognition is both gratifying and humbling. Third, thanks to Peter Zoller for a very favorable rendering of my contributions to science. I can only wonder where Peter was back when I was trying to get the University of New Mexico to raise my salary. It is a great honor to have been awarded a prize of this magnitude and prestige. But prizes are dangerous. The head swells, and it needs to be deflated, and for deflation, I have my two kids, Eleanor Caves and Jeremy Rugenstein, both of whom are scientists, as are their spouses. I happened to open the e-mail informing me I had been awarded the Micius Prize on a Saturday morning a few weeks ago, just as I was about to Skype with Eleanor in the UK and Jeremy in Colorado. -
A First Introduction to Quantum Computing and Information a First Introduction to Quantum Computing and Information Bernard Zygelman
Bernard Zygelman A First Introduction to Quantum Computing and Information A First Introduction to Quantum Computing and Information Bernard Zygelman A First Introduction to Quantum Computing and Information 123 Bernard Zygelman Department of Physics and Astronomy University of Nevada Las Vegas, NV, USA ISBN 978-3-319-91628-6 ISBN 978-3-319-91629-3 (eBook) https://doi.org/10.1007/978-3-319-91629-3 Library of Congress Control Number: 2018946528 © Springer Nature Switzerland AG 2018 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. -
Scientific Report for the Year 2000
The Erwin Schr¨odinger International Boltzmanngasse 9 ESI Institute for Mathematical Physics A-1090 Wien, Austria Scientific Report for the Year 2000 Vienna, ESI-Report 2000 March 1, 2001 Supported by Federal Ministry of Education, Science, and Culture, Austria ESI–Report 2000 ERWIN SCHRODINGER¨ INTERNATIONAL INSTITUTE OF MATHEMATICAL PHYSICS, SCIENTIFIC REPORT FOR THE YEAR 2000 ESI, Boltzmanngasse 9, A-1090 Wien, Austria March 1, 2001 Honorary President: Walter Thirring, Tel. +43-1-4277-51516. President: Jakob Yngvason: +43-1-4277-51506. [email protected] Director: Peter W. Michor: +43-1-3172047-16. [email protected] Director: Klaus Schmidt: +43-1-3172047-14. [email protected] Administration: Ulrike Fischer, Eva Kissler, Ursula Sagmeister: +43-1-3172047-12, [email protected] Computer group: Andreas Cap, Gerald Teschl, Hermann Schichl. International Scientific Advisory board: Jean-Pierre Bourguignon (IHES), Giovanni Gallavotti (Roma), Krzysztof Gawedzki (IHES), Vaughan F.R. Jones (Berkeley), Viktor Kac (MIT), Elliott Lieb (Princeton), Harald Grosse (Vienna), Harald Niederreiter (Vienna), ESI preprints are available via ‘anonymous ftp’ or ‘gopher’: FTP.ESI.AC.AT and via the URL: http://www.esi.ac.at. Table of contents General remarks . 2 Winter School in Geometry and Physics . 2 Wolfgang Pauli und die Physik des 20. Jahrhunderts . 3 Summer Session Seminar Sophus Lie . 3 PROGRAMS IN 2000 . 4 Duality, String Theory, and M-theory . 4 Confinement . 5 Representation theory . 7 Algebraic Groups, Invariant Theory, and Applications . 7 Quantum Measurement and Information . 9 CONTINUATION OF PROGRAMS FROM 1999 and earlier . 10 List of Preprints in 2000 . 13 List of seminars and colloquia outside of conferences . -
Simulation and Programming of Quantum Computers
Simulation and Programming of Quantum Computers Roland Rudiger¨ [email protected] Lecture given at Department of Transportation, University of Applied Sciences and Department of High Performance Computing { Center of Logistics and Expert Systems GmbH, Salzgitter, Germany April 25, 2003 Outline . Quantum computation|basic concepts . Algorithms and simulation . Quantum programming languages . Realization of QCs|present state Quantum computation|basic concepts Introductory remarks and example General remarks on quantum mechanics . Feynman: \I think I can safely say that nobody understands quan- tum mechanics." . Bohr: \Anyone who is not shocked by quantum theory has not understood it." . \Quantum mechanics is a mathematical framework or set of rules for the construction of physical theories." (Nielsen & Chuang [NC00, p. 2]) . framework is highly counter-intuitive: physical states and processes are described in a state space terminology . main differences to classical physics: { superposition principle (At any given time a quantum system can be \in more than one state".) but: Statements in natural language like this might be mis- leading and inadequate (and sometimes wrong). { statistical interpretation (The outcomes of measurements obey probabilistic laws.) . in QM: typically 3 steps: preparation of a state (unitary) time evolution ! ! measurement . the problem: there is no direct intuitive interpretation of the notion of \state": states comprise the statistics of measurement outcomes . a pragmatic advice to students: \Shut up and calculate." An example 1 . spin-2 particle: a potential realization of a 2 level system (a \qubit") . experimental experience: for every given space direction there are exactly two possible measurement outcomes: . ~, where ~ = h , h = Planck's constant ±2 2π . state space: 2-dim Hilbert-space: = C2 H possible choice of basis: ~eup;~edown system states after a measurement of the electron spin in z-direction . -
Annual-Report-BW Ceperley
Annual Report for Blue Waters Allocation January 2016 Project Information o Title: Quantum Simulations o PI: David Ceperley (Blue Waters professor), Department of Physics, University of Illinois Urbana-Champaign o Norm Tubman University of Illinois Urbana-Champaign (former postdoc), Carlo Pierleoni (Rome, Italy), Markus Holzmann(Grenoble, France) o Corresponding author: David Ceperley, [email protected] Executive summary (150 words) Much of our research on Blue Waters is related to the “Materials Genome Initiative,” the federally supported cross-agency program to develop computational tools to design materials. We employ Quantum Monte Carlo calculations that provide nearly exact information on quantum many-body systems and are also able to use Blue Waters effectively. This is the most accurate general method capable of treating electron correlation, thus it needs to be in the kernel of any materials design initiative. Ceperley’s group has a number of funded and proposed projects to use Blue Waters as discussed below. In the past year, we have been running calculations for dense hydrogen in order to make predictions that can be tested experimentally. We have also been testing a new method that can be used to solve the fermion sign problem and to find dynamical properties of quantum systems. Description of research activities and results During the past year, the following 4 grants of which Ceperley is a PI or CoPI, and that involve Blue Waters usage, have had their funding renewed. Access to Blue Waters is crucial for success of these projects. • “Warm dense matter”DE-NA0001789. Computation of properties of hydrogen and helium under extreme conditions of temperature and pressure. -
The Early Years of Quantum Monte Carlo (1): the Ground State
The Early Years of Quantum Monte Carlo (1): the Ground State Michel Mareschal1,2, Physics Department, ULB , Bruxelles, Belgium Introduction In this article we shall relate the history of the implementation of the quantum many-body problem on computers, and, more precisely, the usage of random numbers to that effect, known as the Quantum Monte Carlo method. The probabilistic nature of quantum mechanics should have made it very natural to rely on the usage of (pseudo-) random numbers to solve problems in quantum mechanics, whenever an analytical solution is out of range. And indeed, very rapidly after the appearance of electronic machines in the late forties, several suggestions were made by the leading scientists of the time , - like Fermi, Von Neumann, Ulam, Feynman,..etc- which would reduce the solution of the Schrödinger equation to a stochastic or statistical problem which , in turn, could be amenable to a direct modelling on a computer. More than 70 years have now passed and it has been witnessed that, despite an enormous increase of the computing power available, quantum Monte Carlo has needed a long time and much technical progresses to succeed while numerical quantum dynamics mostly remains out of range at the present time. Using traditional methods for the implementation of quantum mechanics on computers has often proven inefficient, so that new algorithms needed to be developed. This is very much in contrast with what happened for classical systems. At the end of the fifties, the two main methods of classical molecular simulation, Monte Carlo and Molecular Dynamics, had been invented and an impressively rapid development was going to take place in the following years: this has been described in previous works [Mareschal,2018] [Battimelli,2018]. -
The Early Years of Quantum Monte Carlo (2): Finite- Temperature Simulations
The Early Years of Quantum Monte Carlo (2): Finite- Temperature Simulations Michel Mareschal1,2, Physics Department, ULB , Bruxelles, Belgium Introduction This is the second part of the historical survey of the development of the use of random numbers to solve quantum mechanical problems in computational physics and chemistry. In the first part, noted as QMC1, we reported on the development of various methods which allowed to project trial wave functions onto the ground state of a many-body system. The generic name for all those techniques is Projection Monte Carlo: they are also known by more explicit names like Variational Monte Carlo (VMC), Green Function Monte Carlo (GFMC) or Diffusion Monte Carlo (DMC). Their different names obviously refer to the peculiar technique used but they share the common feature of solving a quantum many-body problem at zero temperature, i.e. computing the ground state wave function. In this second part, we will report on the technique known as Path Integral Monte Carlo (PIMC) and which extends Quantum Monte Carlo to problems with finite (i.e. non-zero) temperature. The technique is based on Feynman’s theory of liquid Helium and in particular his qualitative explanation of superfluidity [Feynman,1953]. To elaborate his theory, Feynman used a formalism he had himself developed a few years earlier: the space-time approach to quantum mechanics [Feynman,1948] was based on his thesis work made at Princeton under John Wheeler before joining the Manhattan’s project. Feynman’s Path Integral formalism can be cast into a form well adapted for computer simulation. In particular it transforms propagators in imaginary time into Boltzmann weight factors, allowing the use of Monte Carlo sampling. -
Path Integrals Calculations of Helium Droplets
Imaginary Time Path Integral Calculations of Supersolid Helium David Ceperley Dept. of Physics and NCSA University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA In 1953 Feynman, introduced imaginary-time path integrals to understand superfluid 4He. Path integrals are an exact "isomorphism" between quantum systems and the classical statistical mechanics of ring "polymers" allowing one to understand Bose condensation from the point of view of classical statistical mechanics and to calculate many of its properties. Bose symmetry of the wave function implies that the polymers are allowed to “cross-link'' or exchange. Superfluidity (coupling to the boundaries) is proportional to the mean squared flux of polymers through a surface. Bose condensation is equivalent to the delocalization of the end-end distance of a cut polymer. We have developed specialized simulation methods (Path Integral Monte Carlo) based on the Metropolis Monte Carlo method, to simulate boson systems[1]. Andreev, Lifshitz, Chester, and Leggett suggested in about 1970 that a quantum crystal such as bulk helium-4 under pressure might show both crystallinity and superfluid behavior. Experiments by Kim and Chan within the last two years have found indications for such a supersolid phase. The theoretical explanation of superflow in a crystal assumed vacancies, however, they have not been seen experimentally and computer simulations do not find stable vacancies. The path integral picture allows one to address the question[2] of whether a highly fluctuating quantum crystal is “insulating” or “metallic”. We and others have done Path Integral Monte Carlo calculations of exchange frequencies[3], superfluid density and the condensate fraction[4]. -
Quantum Physics from a to Z
Quantum Physics from A to Z M. Arndt,1 M. Aspelmeyer,1 H. J. Bernstein,2 R. Bertlmann,1 C. Brukner,1 J. P. Dowling,3 J. Eisert,4 A. Ekert,5 C. A. Fuchs,6 D. M. Greenberger,7 M. A. Horne,8 T. Jennewein,9 P. G. Kwiat,10 N. D. Mermin,11 J.-W. Pan,12 E. M. Rasel,13 H. Rauch,14 T. G. Rudolph,15 C. Salomon,16 A. V. Sergienko,17 J. Schmiedmayer,12 C. Simon,18 V. Vedral,19 P. Walther,1 G. Weihs,20 P. Zoller,21 and M. Zukowski22 1University of Vienna, Vienna, Austria 2Hampshire College, Amherst, MA, USA 3Louisiana State University, Baton Rouge, LA, USA 4University of Potsdam, Potsdam, Germany 5Cambridge University, Cambridge, UK 6Lucent Technologies, Murray Hill, NJ, USA 7City College, CUNY, NY, USA 8Stonehill College, Easton, MA, USA 9Austrian Academy of Sciences, Vienna, Austria 10University of Illinois, Urbana-Champaign, IL, USA 11Cornell University, Ithaca, NY, USA 12University of Heidelberg, Heidelberg, Germany 13University of Hannover, Hannover, Germany 14Atomic Institute of the Austrian Universities, Vienna, Austria 15Imperial College, London, United Kingdom 16Ecole Normale Superieure, Paris, France 17Boston University, Boston, MA, USA 18CNRS, Grenoble, France 19University of Leeds, Leeds, UK 20University of Waterloo, Waterloo, Canada 21University of Innsbruck, Innsbruck, Austria 22University of Gdansk, Gdansk, Poland th (Dated: May 20 , 2005) This is a collection of statements gathered on the occasion of the Quantum Physics of Nature meeting in Vienna. Since philosophers are beginning to discuss the “Zeilinger principle” of quantum physics [1, 2, 3] it appears timely to get a community view on what that might be. -
Peter Zoller
Peter Zoller Professor of Physics, University of Innsbruck Research Director, Institute for Quantum Optics and Quantum Information (IQOQI) Austria Academy of Sciences Talk Title: Quantum Variational Optimization of Ramsey Interferometry and Atomic Clocks Abstract: We report a theory [1] - experiment [2] collaborative effort to devise and implement optimal N-atom Ramsey interferometry with variational quantum circuits on a programmable quantum sensor realized with trapped-ions. Optimization is defined relative to a cost function, which in the present study is the Bayesian mean square error of the estimated phase for a given prior distribution, i.e. we optimize for a finite dynamic range of the interferometer, as relevant for atomic clock operation. The quantum circuits are built from global rotations and one-axis twisting operations, as are natively available with trapped ions. On the theory side, low-depth quantum circuits yield results closely approaching the fundamental quantum limits for optimal Ramsey interferometry. Our experimental findings include quantum enhancement in metrology beyond squeezing, and we verify the performance of circuits by both directly using theory predictions of optimal parameters, and performing online quantum-classical feedback optimization to 'self-calibrate' the variational parameters for up to N=26 ions. Successfully demonstrating operation beyond standard squeezing using on-device optimization opens the quantum variational approach to application across a wide array of sensor platforms and tasks. [1] R. Kaubruegger, D. V. Vasilyev, M. Schulte, K. Hammerer, and P. Zoller, arxiv:2102.05593 [2] C. D. Marciniak, T. Feldker, I. Pogorelov, R. Kaubruegger, D.V. Vasilyev, R. van Bijnen, P. Schindler, P. Zoller, R. Blatt, and T. -
Variational Density Matrix Method for Warm Condensed Matter And
Variational Density Matrix Method for Warm Condensed Matter and Application to Dense Hydrogen Burkhard Militzera) and E. L. Pollockb) a)Department of Physics University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 b)Physics Department, Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (August 8, 2018) A new variational principle for optimizing thermal density matrices is intro- duced. As a first application, the variational many body density matrix is written as a determinant of one body density matrices, which are approximated by Gaus- sians with the mean, width and amplitude as variational parameters. The method is illustrated for the particle in an external field problem, the hydrogen molecule and dense hydrogen where the molecular, the dissociated and the plasma regime are described. Structural and thermodynamic properties (energy, equation of state and shock Hugoniot) are presented. I. INTRODUCTION Considerable effort has been devoted to systems where finite temperature ions (treated either classically or quantum mechanically by path integral methods) are coupled to degenerate electrons on the Born-Oppenheimer surface. In contrast, the theory for similar systems with non-degenerate electrons (T a significant fraction of TF ermi) is relatively underdeveloped except at the extreme high T limit where Thomas-Fermi and similar theories apply. In this paper we present a computational approach for systems with non-degenerate electrons analogous to the methods used for ground state many body computations. Although an oversimplification, we may usefully view the ground state computations as consisting of three levels of increasing accuracy [1]. At the first level, the ground state wave function consists of determinants, for both spin species, of single particle orbitals often taken from local density functional theory Φ1(r1) .. -
2014 Blue Waters Update
2014 Blue Waters Update Bill Kramer Blue Waters Director Announcements • Today, Ed Seidel has invited the PIs to lunch in the Alma Mater Room. • The PI's have blue tickets in the back of their badges. • We will take a group photo of all attendees at the first break. • #BWsymp2014 for another chance BW Symposium - May 2014 2 Joint Dinner at Memorial Stadium – Tonight Joint with the Private Sector Program Workshop Attendees BW Symposium - May 2014 3 SETAC NSF PRAC • Paul Woodward, Physics and Astrophysics, University of Minnesota • Tom Cheatham, Chemistry, University of Utah • Patrick Reed, Civil and Environmental Engineering – Systems Optimization, Cornell • Klaus Schulten, Physics and Molecular Dynamic, University of Illinois Urbana-Champaign • David Ceperley, Physics and Material Science, University of Illinois Urbana-Champaign • Tiziana Di Matteo, Physics and Cosmology, Carnegie Mellon University • Dave Randall, Atmospheric Sciences and Climate Colorado State University GLCPC Chair • Joe Paris, Academic & Research Technologies in Information Technology, Northwestern University (Chair for 2013/2014, followed by Jorge Vinals, Structural Mechanics and Biophysics, University of Minnesota, Chair for 2014/2015) University of Illinois at Urbana-Champaign Allocation Chair • Athol Kemball, Atmospheric Sciences, University of Illinois at Urbana-Champaign Industry • Rick Authur, General Electric Global Research, Computer and Software Engineering BW Symposium - May 2014 4 Blue Waters Fellows • 6 Awards (so far) • Substantial Stipend + Blue Waters allocations • 10 other very deserving nominees are being offered Blue Waters allocations • Kenza Arraki, New Mexico State University • Jon Calhoun, University of Illinois at Urbana-Champaign • Sara Kokkila, Stanford University, • Edwin Mathews, University of Notre Dame • Ariana Minot, Harvard University • Derek Vigil-Fowler, University of California, Berkeley BW Symposium - May 2014 5 Blue Waters Usage 2/11/14 – Largest 10 Jobs-Torus View Each dot is a Gemini router and represents 64 AMD integer cores.