DOCSLIB.ORG

Quantum Computing

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Quantum Computing Proc. Natl. Acad. Sci. USA Vol. 95, pp. 11032–11033, September 1998 From the Academy This paper is a summary of a session presented at the Ninth Annual Frontiers of Science Symposium, held November 7–9, 1997, at the Arnold and Mabel Beckman Center of the National Academies of Sciences and Engineering in Irvine, CA. Quantum computing GILLES BRASSARD*†,ISAAC CHUANG‡,SETH LLOYD§, AND CHRISTOPHER MONROE¶ *De´partement d’informatique et de recherche ope´rationnelle, Universite´ de Montre´al, C.P. 6128, succursale centre-ville, Montre´al, QC H3C 3J7 Canada; ‡IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120; §Massachusetts Institute of Technology, Department of Mechanical Engineering, MIT 3-160, Cambridge, MA 02139; and ¶National Institute of Standards and Technology, Time and Frequency Division, 325 Broadway, Boulder, CO 80303 Quantum computation is the extension of classical computa- Quantum parallelism arises because a quantum operation tion to the processing of quantum information, using quantum acting on a superposition of inputs produces a superposition of systems such as individual atoms, molecules, or photons. It has outputs. For example, consider some function f and a quantum the potential to bring about a spectacular revolution in com- logic circuit U that computes it by mapping quantum register puter science. Current-day electronic computers are not fun- ux,0& to output ux, f(x)&. Let x and y be two distinct inputs, and damentally different from purely mechanical computers: the prepare the superposition (ux,0&1uy,0&)y=2. Applying U operation of either can be described completely in terms of produces (ux, f(x)&1uy, f(y)&)y=2: the value of function f is classical physics. By contrast, computers could in principle be computed on both inputs x and y even though circuit U is used built to profit from genuine quantum phenomena that have no once only. This works for even larger superpositions: applying ( u & 5 2ny2 classical analogue, such as entanglement and interference, U to xc x,0, where c 2 is a normalization factor, gives ( u & sometimes providing exponential speed-up compared with xc x, f(x) , an equal superposition of all input–output pairs. classical computers. An exponential amount of computation has been achieved in the Quantum Information. All computers manipulate informa- time it takes to compute the function on a single input. Unfor- tion, and the unit of quantum information is the quantum bit, tunately, if this exponentially rich state is measured, the entire or qubit. Classical bits can take either value 0 or 1, but qubits state collapses into a single randomly chosen input–output pair can be in a linear superposition of the two classical states. If we ux, f(x)&. Indeed, it would have been easier to choose x at denote the classical bits by u0& and u1&, a quantum bit can be in random before computing f(x) by classical means! To make any state au0&1bu1&, where a and b are complex numbers good use of quantum parallelism, we also must use the notion called amplitudes subject to uau2 1 ubu2 5 1. Any attempt at of quantum interference. measuring qubits induces an irreversible disturbance. For Imagine that we have an unknown function f that has a example, the most direct measurement on au0&1bu1& results one-bit input and a one-bit output, and that we are interested in the qubit making a probabilistic decision: with probability neither in the value of f(0) nor that of f(1), but rather in uau2, it becomes u0& and with complementary probability ubu2,it whether or not those two values are equal. If we have no other becomes u1&; in either case the measurement apparatus tells us access to f than a classical circuit to compute it, nothing better which choice has been taken, but all previous memory of the can be done than to run the circuit twice, to obtain and then original amplitudes a and b is lost. compare f(0) and f(1). However, if we are given a quantum Unlike classical bits, where a single string of n zeros and ones circuit U that transforms input ux, b& into output ux, bQf(x)&, suffices to describe the state of n bits, a physical system of n where Q denotes addition modulo two, we can do better. qubits requires 2n complex numbers to describe its state. For Prepare the first input in state (u0&1u1&)y=2 and the second au &1bu &1gu & example, two qubits can be in the state 00 01 10 input in state (u0&2u1&)y=2. Put together, the input state is 1 du & a b g d 11 for arbitrary complex numbers , , , and subject (u00&2u01&1u10&2u11&)y2. Applying U, the output is (u0, f(0)& uau2 1 ubu2 1 ugu2 1 udu2 5 only to the constraint 1. 2 u0, f(0)&1u1, f(1)&2u1, f(1)&)y2, where x denotes the Another feature of qubits is the property of entanglement. complement of bit x. Now apply to the first qubit the quantum u &2u &2u &1u & y Consider the two-qubit state ( 00 01 10 11 ) 2. This transformation that maps u0& to (u0&1u1&)y=2 and u1& to (u0& state is less complicated than it actually looks, because it can 2 u1&)y=2. The reader is encouraged to verify that the first be factored into the product of two one-qubit states, each of qubit ends up in the state uf(0)Qf(1)&: measuring this qubit now u &2u & y= which is ( 0 1 ) 2. Similarly, many n-qubit states can be produces the desired answer even though the quantum circuit U written in factored form and thus require only 2n numbers for to compute function f has been invoked once only. n their description, which is much less than the 2 numbers Intuitively, what happens is that interference occurs between u & generally required. However, some special states such as ( 01 computation paths. For example, there are two logical paths for 2 u & y= 10 ) 2 cannot be factored. When these two qubits are the case f(0) 5 f(1) 5 0 from the initial input state to output u10&: measured, they yield either 0 and 1 or 1 and 0, with equal one via f(0) 5 0, whose amplitude is 1y2=2, and one via f(1) 5 y= 2 5 y probability (1 2) 1 2, but which of these two outcomes 0, whose amplitude is 21y2=2. Both paths appear to have will occur is not determined until the measurement is actually nonzero probability of being observed, but actually they interfere performed. This has no classical analogue. destructively in a way that output u10& is in fact never observed. Quantum Computing. Computers that thrive on entangled Interference also can be constructive, as in the case for output u00&, quantum information could run exponentially faster than n which is twice more likely to be observed than the sum of the classical computers because n qubits require 2 numbers for probabilities associated with the two paths leading to it. their description. A few simple operations on these qubits can n The art of quantum programming is the clever exploitation affect all 2 numbers through the use of quantum parallelism of quantum interference to solve interesting problems by and quantum interference. reinforcing the probability of obtaining desired results while at © 1998 by The National Academy of Sciences 0027-8424y98y9511032-3$2.00y0 †To whom reprint requests should be addressed. email: brassard@iro. PNAS is available online at www.pnas.org. umontreal.ca. 11032 From the Academy: Brassard et al. Proc. Natl. Acad. Sci. USA 95 (1998) 11033 the same time reducing or even annihilating the probability of obtaining unwanted results. It took nearly ten years after David Deutsch first suggested that such techniques could be useful (following earlier work by Paul Benioff and Richard Feynman) (1–3) that Peter Shor discovered in 1994 a quantum algorithm for efficiently factoring large numbers (4). This attracted considerable interest, not only for its tremendous cryptographic significance, but also as a first indication that quantum computers could be genuinely faster than classical computers for solving natural problems. Subsequently, an- other application was discovered: imagine searching for the name of a stranger whose phone number you know, given an ordinary phone directory ordered alphabetically by names. FIG. 2. Chloroform molecule as a two-bit quantum computer. Classically, this would require one to sift through one-half of the directory on average. Lov Grover’s quantum search algo- ties, but there appear to be no fundamental limits to the scaling. rithm (5) solves this problem in about square-root the amount Another nearly ideal physical system that can be used as of time required classically. This algorithm has been extended quantum computer is a single molecule, in which nuclear spins and applied to database searches and cryptography (6). of individual atoms represent qubits (9). Using NMR tech- All this theory of quantum computation is very nice, but is it niques, invented in the 1940’s and widely used in chemistry and only that: a theory? For the moment, no large-scale quantum medicine today, these spins can be manipulated, initialized, computation has been achieved in the laboratory, and there is no and measured. Most NMR applications treat spins as little ‘‘bar conclusive evidence than one will ever be. Nevertheless, several magnets,’’ whereas in reality, the naturally well isolated nuclei teams around the globe are working at small-scale prototypes. are nonclassical objects. The spins’ quantum behavior can be Next, we give a glimpse into that experimental world.
Load more

Recommended publications
  • Christopher Monroe Joint Quantum Institute University of Maryland and NIST
    PEP Seminar Series Wednesday, September 10th, 2:30 PM, Babbio 210 Christopher Monroe Joint Quantum Institute University of Maryland and NIST Trapped atomic ions are among the most promising candidates for a future quantum information processor, with each ion storing a single quantum bit (qubit) of information. All of the fundamental quantum operations have been demonstrated on this system, and the central challenge now is how to scale the system to larger numbers of qubits. The conventional approach to forming entangled states of multiple trapped ion qubits is through the local Coulomb interaction accompanied by appropriate state-dependent optical forces. Recently, trapped ion qubits have been entangled through a photonic coupling, allowing qubit memories to be entangled over remote distances. This coupling may allow the generation of truly large-scale entangled quantum states, and also impact the development of quantum repeater circuits for the communication of quantum information over geographic distances. I will discuss several options and issues for such atomic quantum networks, along with state-of-the-art experimental progress. Chris Monroe obtained his PhD at the University of Colorado at Boulder in 1992 under Carl Weiman. He worked as a Postdoctoral Researcher at the National Institute of Standard and Technology at Boulder with David Wineland. He was a Professor at the University of Michigan at the Department of Physics (2003- 2007) and at the Department of Electrical Engineering and Computer Science (2006-2007). He was the Director of FOCUS Center (an NSF Physics Frontier Center) at Michigan (2006-2007). He is a fellow of APS, the Institute of Physics (UK), and also at Joint Quantum Institute at the University of Maryland.
    [Show full text]
  • Christopher Monroe: Biosketch
    Christopher Monroe: Biosketch Christopher Monroe was born and raised outside of Detroit, MI, and graduated from MIT in 1987. He received his PhD in Physics at the University of Colorado, Boulder, studying with Carl Wieman and Eric Cornell. His work paved the way toward the achievement of Bose-Einstein condensation in 1995 and the Nobel Prize in Physics for Wieman and Cornell in 2001. From 1992-2000 he was a postdoc then staff physicist at the National Institute of Standards and Technology (NIST) in the group of David Wineland, leading the team that demonstrated the first quantum logic gate in any physical system. Based on this work, Wineland was awarded the Nobel Prize in Physics in 2012. In 2000, Monroe became Professor of Physics and Electrical Engineering at the University of Michigan, where he pioneered the use of single photons as a quantum conduit between isolated atoms and demonstrated the first atom trap integrated on a semiconductor chip. From 2006-2007 was the Director of the National Science Foundation Ultrafast Optics Center at the University of Michigan. In 2007 he became the Bice Zorn Professor of Physics at the University of Maryland (UMD) and a Fellow of the Joint Quantum Institute between UMD, NIST, and NSA. He is also a Fellow of the Center for Quantum Information and Computer Science at UMD, NIST, and NSA. His Maryland team was the first to teleport quantum information between matter separated by a large distance; they pioneered the use of ultrafast optical techniques for controlling atomic qubits and for quantum simulations of magnetism; and most recently demonstrated the first programmable and reconfigurable quantum computer.
    [Show full text]
  • Steven Olmschenk Cv 2019
    STEVEN OLMSCHENK Denison University Email: [email protected] Department of Physics & Astronomy Office Phone: 740.587.8661 100 West College Street Website: denison.edu/iqo Granville, Ohio 43023 Education o University of Michigan, Ann Arbor, MI Ph.D. in Physics, Advisor: Professor Christopher Monroe (August 2009) Thesis: “Quantum Teleportation Between Distant Matter Qubits” M.S.E. in Electrical Engineering (August 2007) M.Sc. in Physics (December 2005) o University of Chicago, Chicago, IL B.A. in Physics with Specialization in Astrophysics, Advisor: Professor Mark Oreglia (June 2004) Thesis: “Searching for Bottom Squarks” B.S. in Mathematics (June 2004) Experience o Associate professor, Denison University August 2018 – Present {Assistant professor, August 2012 – August 2018} Courses taught include: General Physics II (Physics 122); Principles of Physics I: Quarks to Cosmos (Physics 125); Modern Physics (Physics 200); Electronics (Physics 211); and Introduction to Quantum Mechanics (Physics 330). Research focused on experimental atomic physics, quantum optics, and quantum information with trapped atomic ions. o Postdoctoral researcher: Ultracold atomic physics with optical lattices, Supervisors: Doctor James (Trey) V. Porto and Doctor William D. Phillips, National Institute of Standards and Technology July 2009 – July 2012 Ultracold atoms confined in an optical lattice to study strongly correlated many-body states and for applications in quantum information science. o Graduate research assistant: Trapped ion quantum computing, Advisor: Professor Christopher Monroe, University of Michigan/Maryland September 2004 – July 2009 Advancements in quantum information science accomplished through experimental study of individual atomic ions and photons. o Earlier research: High Energy Physics (B.A. thesis); Solar Physics (NSF REU); Radio Astronomy.
    [Show full text]
  • Surprising New States of Matter Called Time Crystals Show the Same Symmetry Properties in Time That Ordinary Crystals Do in Space by Frank Wilczek
    PHYSICS CRYSTAL S IN TIME Surprising new states of matter called time crystals show the same symmetry properties in time that ordinary crystals do in space By Frank Wilczek Illustration by Mark Ross Studio 28 Scientific American, November 2019 © 2019 Scientific American November 2019, ScientificAmerican.com 29 © 2019 Scientific American Frank Wilczek is a theoretical physicist at the Massachusetts Institute of Technology. He won the 2004 Nobel Prize in Physics for his work on the theory of the strong force, and in 2012 he proposed the concept of time crystals. CRYSTAL S are nature’s most orderly suBstances. InsIde them, atoms and molecules are arranged in regular, repeating structures, giving rise to solids that are stable and rigid—and often beautiful to behold. People have found crystals fascinating and attractive since before the dawn of modern science, often prizing them as jewels. In the 19th century scientists’ quest to classify forms of crystals and understand their effect on light catalyzed important progress in mathematics and physics. Then, in the 20th century, study of the fundamental quantum mechanics of elec- trons in crystals led directly to modern semiconductor electronics and eventually to smart- phones and the Internet. The next step in our understanding of crystals is oc- These examples show that the mathematical concept IN BRIEF curring now, thanks to a principle that arose from Al- of symmetry captures an essential aspect of its com- bert Einstein’s relativity theory: space and time are in- mon meaning while adding the virtue of precision. Crystals are orderly timately connected and ultimately on the same footing.
    [Show full text]
  • The Quantum Times
    TThhee QQuuaannttuumm TTiimmeess APS Topical Group on Quantum Information, Concepts, and Computation autumn 2007 Volume 2, Number 3 Science Without Borders: Quantum Information in Iran This year the first International Iran Conference on Quantum Information (IICQI) – see http://iicqi.sharif.ir/ – was held at Kish Island in Iran 7-10 September 2007. The conference was sponsored by Sharif University of Technology and its affiliate Kish University, which was the local host of the conference, the Institute for Studies in Theoretical Physics and Mathematics (IPM), Hi-Tech Industries Center, Center for International Collaboration, Kish Free Zone Organization (KFZO) and The Center of Excellence In Complex System and Condensed Matter (CSCM). The high level of support was instrumental in supporting numerous foreign participants (one-quarter of the 98 registrants) and also in keeping the costs down for Iranian participants, and having the conference held at Kish Island meant that people from around the world could come without visas. The low cost for Iranians was important in making the Inside… conference a success. In contrast to typical conferences in most …you’ll find statements from of the world, Iranian faculty members and students do not have the candidates running for various much if any grant funding for conferences and travel and posts within our topical group. I therefore paid all or most of their own costs from their own extend my thanks and appreciation personal money, which meant that a low-cost meeting was to the candidates, who were under essential to encourage a high level of participation. On the plus a time-crunch, and Charles Bennett side, the attendees were extraordinarily committed to learning, and the rest of the Nominating discussing, and presenting work far beyond what I am used to at Committee for arranging the slate typical conferences: many participants came to talks prepared of candidates and collecting their and knowledgeable about the speaker's work, and the poster statements for the newsletter.
    [Show full text]
  • Quantum Computing with Atoms Christopher Monroe Computing and Information
    Quantum Computing with Atoms Christopher Monroe Computing and Information Alan Turing (1912-1954) universal computing machines moving CPU 011 Claude Shannon (1916-2001) quantify information: the bit read/write device 1 0 1 1 0 0 1 푘 memory tape 퐻 = − ෍ 푝푖푙표푔2푝푖 푖=1 vacuum tubes ENIAC (1946) МЭСМ (1949) solid-state transistor Colossus (1943) (1947) Moore’s Law exponential growth in computing Transistor density relative to 1978 Richard 100,000 Feynman 10,000 1,000 100 There's Plenty of Room at the Bottom (1959) 10 “When we get to the very, very small world – say circuits of seven atoms – we have a lot of new things that would happen 1 that represent completely new opportunities for design. Atoms 1980 1990 2000 2010 2018 on a small scale behave like nothing on a large scale, for they satisfy the laws of quantum mechanics…” Quantum Information Science |0 state |0 state Prob = |a|2 Quantum bits |1 state |1 state superposition measurement: Prob = |b|2 a|0 + b|1 “state collapse” |0|0 state Entanglement OR superposition |1|1 state a|0|0 + b|1|1 entanglement: “wiring without wires” Good News… …Bad News… …Good News! parallel processing measurement gives quantum interference on 2N inputs random result e.g., N=3 qubits f(x) f(x) a |000 + a |001 + a |010 + a |011 depends 0 1 2 3 on all inputs a4 |100 + a5|101 + a6 |110 + a7 |111 N=300 qubits have more configurations than there are David Deutsch particles in the universe! (early 1990s) Application: Factoring Numbers A quantum computer can factor numbers exponentially faster than classical computers P.
    [Show full text]
  • Remote Quantum Computing Is the Future
    A personal take on science and society World view By Christopher Monroe Remote quantum computing is the future Conditions created by the COVID-19 shutdown EURIQA (Error-corrected Universal Reconfigurable Ion are delivering one experiment’s ‘best data ever’. trap Quantum Archetype) began operating autonomously It would be in April 2019. The whole system now sits in a 1-metre-cubed box. It’s rarely opened. One researcher visits the lab for he COVID-19 pandemic and shutdown have been great if some 10–20 minutes once a week to reboot the odd computer disastrous for many people. But one research quantum that has frozen or power supply that has tripped. project in my lab has been humming along, tak- components Since my university went into COVID-19 shutdown in ing the best data my team has ever seen. It is an March, EURIQA has kept running — all day, every day. And advanced ‘ion trap’ quantum computer, which were ‘plug- the data have been excellent because the campus has been Tuses laser beams to control an array of floating atoms. and-play’, a ghost town. The lab’s temperature hasn’t wavered and We spent three years setting it up to run remotely and like the flash there’s little vibrational noise in the unoccupied build- autonomously. Now, we think more labs should run quan- ing. It’s one of very few university quantum experiments tum-computing experiments like this, to speed up research. memory on a making real progress right now. Quantum computers exploit the weird behaviour of mat- smartphone But there’s a bigger picture.
    [Show full text]
  • Qnas with Christopher Monroe QNAS
    QNAS QnAs with Christopher Monroe QNAS Chris Samoray, Science Writer Classic computing can take credit for technology ranging from mobile phones to supercomputers. But in recent years, a budding counterpart to these con- ventional devices has emerged: quantum computers. Whereas classic computing sometimes fails to solve complex calculations, such as factoring hundred-digit numbers, quantum computing holds the potential to easily tackle such problems. The field of quantum computing has attracted researchers, such as National Academy of Sciences member Christopher Monroe. An experimental atomic physicist at the University of Maryland and fellow of the Joint Quantum Institute and the Joint Center for Quantum Information and Computer Science in Maryland, Monroe uses lasers to exploit atomic particles to study complex computa- tional problems. Monroe spoke to PNAS about how quantum computing might evolve. Christopher Monroe. PNAS: Can you describe some of the basic mechanics of quantum computing? We manipulate them without looking. In our platform of Monroe: It all comes down to the superposition atoms, lasers allow us to change the atomic qubit state principle, in which a quantum system can exist in without revealing it. multiple states at the same time. Consider the funda- PNAS: mental unit of information: the bit. A bit is binary Since the early 1980s, physicists and mathe- information that can be a 0 or a 1. A quantum bit, or maticians have posited that the quantum world could qubit, can be in a superposition of both 0 and 1 as long be harnessed to assist the development of advanced as it’s isolated and unobserved.
    [Show full text]
  • Development of Quantum Interconnects (Quics) for Next-Generation Information Technologies
    Development of Quantum InterConnects (QuICs) for Next-Generation Information Technologies 1 2 1 3 4 5 David Awschalom ,​ Karl K. Berggren ,​ Hannes Bernien ,​ Sunil Bhave ,​ Lincoln D. Carr ,​ Paul Davids ,​ ​ 6 ​ 2 7,​ 8 ​9 10, 11​ , 12 ​ Sophia E. Economou ,​ Dirk Englund ,​ Andrei Faraon ,​ Marty Fejer ,​ Saikat Guha ,​ Martin V. 13 ​ 14, 15 ​ 1 ​ 16, 17 ​ 18 ​ 19, 20 Gustafsson ,​ Evelyn Hu ,​ Liang Jiang ,​ Jungsang Kim ,​ Boris Korzh ,​ Prem Kumar ,​ Paul G. 21, 22 ​ ​ 14, 15 ​ 15, 23 ​ 9 ​ ​ 24, 25, 26 Kwiat ,​ Marko Lončar *​ , Mikhail D. Lukin ,​ David A. B. Miller ,​ Christopher Monroe ,​ ​ 27 ​ 14, 15 ​ 28 ​ 29, 30 ​ Sae Woo Nam ,​ Prineha Narang ,​ Jason S. Orcutt ,​ Michael G. Raymer *​ , Amir H. 9 ​ 31 ​ 25, 32 ​ 9, 33 ​ 9 25, 34 Safavi-Naeini ,​ Maria Spiropulu ,​ Kartik Srinivasan ,​ Shuo Sun ,​ Jelena Vučković ,​ Edo Waks ,​ ​ ​ 24, 34, 35, 36 ​ 3, 37​ 10, 38 ​ ​ Ronald Walsworth ,​ Andrew M. Weiner ,​ Zheshen Zhang ​ ​ ​ 1 P​ ritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637 2 D​ epartment of Electrical Engineering and Computer Science, MIT, Cambridge, MA 02139 3 S​ chool of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907 4 D​ epartment of Physics, 1500 Illinois St., Colorado School of Mines, Golden, Colorado, 80401 5 P​ hotonic & Phononic Microsystems, Sandia National Laboratory, Albuquerque, NM 87185 6 D​ epartment of Physics, Virginia Tech, Blacksburg, VA 24061 7 T​ .J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125 8 K​ avli Nanoscience Institute, California Institute of Technology, Pasadena, CA 91125 9 E​ .L. Ginzton Laboratory, Stanford University, Stanford, CA 94305 10 C​ ollege of Optical Sciences, The University of Arizona, Tucson, AZ 85721 11 D​ epartment of Electrical and Computer Engineering, The University of Arizona, Tucson, AZ 85721 12 D​ epartment of Applied Mathematics, The University of Arizona, Tucson, AZ 85721 13 R​ aytheon BBN Technologies, Cambridge, MA 02138 14 J​ ohn A.
    [Show full text]
  • Quantum Research At
    UMD: UNIQUELY POSITIONED TO LEAD THE NEXT QUANTUM REVOLUTION “We are witnessing the beginning DEVELOPING SOLUTIONS FOR CRITICAL SCIENTIFIC CHALLENGES of a second quantum revolution. The complexity of our modern scientific The first revolution relied on challenges—such as mapping the human brain, advancing personalized medicine and what is today seen as the ‘ordinary’ safeguarding communications networks— features of quantum theory. demands faster processing and greater technological advances. By building a MAJOR TECHNOLOGICAL ADVANCES The second revolution is based device based on quantum bits, or qubits, it may be possible to store, process and THE NEXT on the truly weird aspects of BIG ADVANCE? transmit information faster, better and The Second quantum physics.” 2007 Quantum Revolution more securely than today’s technology. 2000 1994 New Era of THE FUTURE 1980 The Rise Dr. William Phillips Smartphones and 1954 The Dawn of the of the Internet Hand-held Devices NOBEL LAUREATE AND FELLOW The Birth of Personal Computer OF THE JOINT QUANTUM INSTITUTE OF 1905 1903 Semiconductor THE UNIVERSITY OF MARYLAND AND 1900 The Birth of WHY MARYLAND? The Birth of Electronics THE NATIONAL INSTITUTE OF STANDARDS Quantum Mechanics • World-Renowned Expertise, with nearly Aviation OF QUANTUM AND TECHNOLOGY 200 Dedicated Researchers • Three Quantum Research Centers WORLD-CHANGING POTENTIAL 1800 Focused on Physics, Computer Science The last three centuries have featured and Engineering 1760-1840 defining moments of innovation that • New State of the Art Facility for Quantum The Industrial RESEARCH changed the course of humankind. Much Research Activity Revolution 1700 of the technology that characterized 20th • Key Location in Washington D.C.
    [Show full text]
  • ¹ 2002 WILEY-VCH Verlag Gmbh & Co. Kgaa, Weinheim 1439-4235/02
    736 ¹ 2002 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1439-4235/02/03/09 $ 20.00+.50/0 CHEMPHYSCHEM 2002, 3, 736 ± 753 When Atoms Behave as Waves: Bose ± Einstein Condensation and the Atom Laser (Nobel Lecture) Wolfgang Ketterle*[a] KEYWORDS: alkali elements ¥ Bose ± Einstein condensates ¥ cooling ¥ low temperature physics ¥ quantum optics The lure of lower temperatures has attracted physicists for the past century, and with each advance towards absolute zero, new and rich physics has emerged. Laypeople may wonder why ™freezing cold∫ is not cold enough. But imagine how many aspects of nature we would miss if we lived on the surface of the sun. Without inventing refrigerators, we would only know gaseous matter and never observe liquids or solids, and miss the beauty of snowflakes. Cooling to normal earthly temper- atures reveals these dramatically different states of matter, but this is only the beginning: Many more states appear with further cooling. The approach into the kelvin range was rewarded with the discovery of superconductivity in 1911 and of superfluidity in Figure 1. Annual number of published papers, which have the words ™Bose∫ and helium-4 in 1938. Cooling into the millikelvin regime revealed ™Einstein∫ in their title, abstracts, or keywords. The data were obtained by the superfluidity of helium-3 in 1972. The advent of laser cooling searching the ISI (Institute for Scientific Information) database. in the 1980s opened up a new approach to ultralow temperature physics. Microkelvin samples of dilute atom clouds were and with mass m can be regarded as quantum-mechanical generated and used for precision measurements and studies wavepackets that have a spatial extent on the order of a thermal of ultracold collisions.
    [Show full text]
  • Quantum Computing and Quantum Simulation with Atoms
    This abstract was submitted to PQE-2019, the 49th Winter Colloquium on the Physics of Quantum Electronics. Submitted by Christopher Monroe on Mon Dec 10 11:24:16 CST 2018. See the program for placement of this presentation. Quantum Computing and Quantum Simulation with Atoms C. Monroe Joint Quantum Institute, Institute for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, MD IonQ, Inc, College Park, MD Isolated atomic systems are the cleanest platform for scalable quantum information processing. The inherent stability and replicability enjoyed by atomic clock qubits cannot be matched in any solid-state systems, from semiconductor spins and quantum dot qubits to superconducting circuitry. Moreover, atomic qubits are not hard-wired but connected with externally applied fields (optical or microwave) that allow the quantum connectivity to be gated and reconfigured. This key attribute allows atomic qubits to be readily and efficiently adapted to any future quantum computation or simulation task. Atomic qubit control systems have not yet been engineered to the same degree as solid-state systems, but this represents an enormous opportunity for the future fabrication of an atomic-based quantum computing or simulator. Here, the challenges do not lie in the fundamental quantum nature of the qubit, but the engineering of the optical/microwave control system. Solid-state qubits, on the other hand, have significant physics hurdles stemming from imperfections in the materials that host the qubit, and how such qubit imperfections and noise scale with qubit number and circuit depth. This session will extensively cover the state-of-the-art in the use of atomic ions and neutral Rydberg atoms in the development of a scalable quantum computer/simulator.
    [Show full text]