DOCSLIB.ORG

Schwab-Roukes-PT-July05.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Schwab-Roukes-PT-July05.Pdf Putting Mechanics into Quantum Mechanics Nanoelectromechanical structures are starting to approach the ultimate quantum mechanical limits for detecting and exciting motion at the nanoscale. Nonclassical states of a mechanical resonator are also on the horizon. Keith C. Schwab and Michael L. Roukes verything moves! In a world dominated by electronic achieved to read out those devices, now bring us to the Edevices and instruments it is easy to forget that all realm of quantum mechanical systems. measurements involve motion, whether it be the motion of electrons through a transistor, Cooper pairs or quasiparti- The quantum realm cles through a superconducting quantum interference de- What conditions are required to observe the quantum prop- vice (SQUID), photons through an optical interferome- erties of a mechanical structure, and what can we learn ter—or the simple displacement of a mechanical element. when we encounter them? Such questions have received Nanoscience today is driving a resurgence of interest in considerable attention from the community pursuing grav- mechanical devices, which have long been used as front itational-wave detection: For more than 25 years, that com- ends for sensitive force detectors. Among prominent his- munity has understood that the quantum properties of me- torical examples are Coulomb’s mechanical torsion bal- chanical detectors will impose ultimate limits on their force 6,7 ance, which allowed him in 1785 to establish the inverse- sensitivity. Through heroic and sustained efforts, the square force law of electric charges, and Cavendish’s Laser Interferometer Gravitational Wave Observatory mechanical instrument that allowed him in 1798 to meas- (LIGO) with a 10-kg test mass, and cryogenic acoustic de- ure the gravitational force between two lead spheres. tectors with test masses as large as 1000 kg, currently Today, micro- and nanoelectromechanical systems achieve displacement sensitivities only a factor of about 30 (MEMS and NEMS) are widely employed in ways similar from the limits set by the uncertainty principle. to those early force detectors, yet with vastly greater force But the quantum-engineering considerations for me- and mass sensitivity—now pushing into the realm of chanical detectors are not exclusive to the realm of gravi- zeptonewtons (10⊗21 N) and zeptograms (10⊗21 g). These ul- tational-wave physics. In the introduction to their pio- traminiature sensors also can provide spatial resolution at neering book on quantum measurement, Vladimir the atomic scale and vibrate at frequencies in the giga- Braginsky and Farid Khalili envisage an era when quan- hertz range.1 Among the breadth of applications that have tum considerations become central to much of commercial 7 become possible are measurements of forces between in- engineering. Today, we are approaching that time— dividual biomolecules,2 forces arising from magnetic reso- advances in the sensitivity of force detection for new types nance of single spins,3 and perturbations that arise from of scanning force microscopy point to an era when me- mass fluctuations involving single atoms and molecules.4 chanical engineers will have to include \ among their list The patterning of mechanical structures with nanometer- of standard engineering constants. scale features is now commonplace; figure 1 and the cover Several laboratories worldwide are pursuing mechan- display examples of current devices. ical detection of single nuclear spins. That goal is espe- The technological future for small mechanical devices cially compelling in light of the recent success of Dan clearly seems bright, yet some of the most intriguing ap- Rugar and colleagues at IBM in detecting a single electron plications of NEMS remain squarely within the realm of spin with a MEMS device (see figure 1b and PHYSICS 3 fundamental research. Although the sensors for the appli- TODAY, October 2004, page 22). However, nuclear spins ⊗21 cations mentioned above are governed by classical physics, generate mechanical forces of about 10 N, more than the imprint of quantum phenomena upon them can now 1000 times smaller than the forces from single electron be readily seen in the laboratory. For example, the Casimir spins. One ultimate application of this technique, struc- effect, arising from the zero-point fluctuations of the elec- tural imaging of individual proteins, will involve millions tromagnetic vacuum, can drive certain small mechanical of bits of data and require measurements to be carried out devices with a force of hundreds of piconewtons and pro- not on the current time scale of hours, but over microsec- duce discernible motion in the devices.5 But it is now pos- onds. Detecting such small forces within an appropriate sible, and perhaps even more intriguing, to consider the measurement time will necessitate new quantum meas- intrinsic quantum fluctuations—those that belong to the urement schemes at high frequencies, a significant chal- mechanical device itself. The continual progress in shrink- lenge. Yet the payoff, originally envisaged by John Sidles, ing devices, and the profound increases in sensitivity will be proportionately immense: three-dimensional, chemically specific atomic imaging of individual macro- Keith Schwab is a senior physicist at the National Security molecules.8 Agency’s Laboratory for Physical Sciences in College Park, The direct study of quantum mechanics in micron- and Maryland. Michael Roukes is Director of the Kavli Nanoscience submicron-scale mechanical structures is every bit as at- Institute and is a professor of physics, applied physics, and bio- tractive as the actual applications of MEMS and NEMS.9 engineering at the California Institute of Technology in Pasadena. With resonant frequencies from kilohertz to gigahertz, low 36 July 2005 Physics Today © 2005 American Institute of Physics, S-0031-9228-0507-010-9 a b Figure 1. Nanoelectro- mechanical devices. (a) A 20-MHz nanome- chanical resonator ca- pacitively coupled to a single-electron transistor (Keith Schwab, Labora- 2mm tory for Physical Sci- ences).11 (b) An ultrasen- sitive magnetic force detector that has been used to detect a single c d electron spin (Dan Rugar, IBM).3 (c) A tor- sional resonator used to study Casimir forces and look for possible correc- tions to Newtonian grav- itation at short length scales (Ricardo Decca, Indiana University– Purdue University Indi- anapolis). (d) A paramet- ric radio-frequency me- chanical amplifier that provides a thousandfold boost of signal displace- ments at 17 MHz e f (Michael Roukes, Cal- tech). (e) A 116-MHz nanomechanical res- onator coupled to a single-electron transistor (Andrew Cleland, Uni- versity of California, W 10 Source Drain Santa Barbara). dz (f) A tunable carbon nanotube resonator op- erating at 3–300 MHz (Paul McEuen, Cornell Gate University).14 dissipation, and small masses (10⊗15–10⊗17 kg), these devices A is the number of atoms in the structure. Knowing the are well suited to such explorations. Their dimensions not amplitude and phase of all the mechanical modes is equiv- only make them susceptible to local forces, but also make it alent to having complete knowledge of the position and mo- possible to integrate and tightly couple them to a variety of mentum of every atom in the device. Continuum mechan- interesting electronic structures, such as solid-state two- ics, with bulk parameters such as density and Young’s level systems (quantum bits, or qubits), that exhibit quan- modulus, provides an excellent description of the mode tum mechanical coherence. In fact, the most-studied sys- structure and the classical dynamics, because the wave- tems, nanoresonators coupled to various superconducting lengths (100 nm–10 mm) of the lowest-lying vibrational qubits, are closely analogous to cavity quantum electrody- modes are long compared to the interatomic spacing. namics, although they are realized in a very different pa- It is natural to make the distinction between nano- rameter space. mechanical modes and phonons: The former are low- frequency, long-wavelength modes strongly affected by the Quantized nanomechanical resonators boundary conditions of the nanodevice, whereas the latter The classical and quantum descriptions of a mechanical res- are vibrational modes with wavelengths much smaller onator are very similar to those of the electromagnetic field than typical device dimensions. Phonons are relatively un- in a dielectric cavity: The position- and time- dependent me- affected by the geometry of the resonator and, except in chanical displacement u(r,t) is the dynamical variable anal- devices such as nanotubes that approach atomic dimen- ogous to the vector potential A(r, t). In each case, a wave sions, are essentially identical in nature to phonons in an equation constrained by boundary conditions gives rise to a infinite medium. spectrum of discrete modes. For sufficiently low excitation It is an assumption that quantum mechanics should amplitudes, for which nonlinearities can be ignored, the en- even apply for such a large, distributed mechanical struc- ergy of each mode is quadratic in both the displacement and ture. Setting that concern aside for the moment, one can momentum, and the system can be described as essentially follow the standard quantum mechanical protocol to es- independent simple harmonic oscillators. tablish that the energy of each mode is quantized: 1 Spatially extended mechanical devices, such as those E ⊂ \w(N ⊕ /2), where N ⊂ 0, 1, 2, . is the occupation fac- in figure 1, possess a total
Load more

Recommended publications
  • Nanoelectromechanical Systems Face the Future Michael Roukes
    physicsworldarchive.iop.org Nanoelectromechanical systems face the future Michael Roukes From Physics World February 2001 © IOP Publishing Ltd 2007 ISSN: 0953-8585 Institute of Physics Publishing Bristol and Philadelphia Downloaded on Tue Oct 09 05:06:27 BST 2007 [198.11.27.40] FEATURES A host of novel applications and new physics could be unleashed as microelectromechanical systems shrink towards the nanoscale Nanoelectromechanical systems face the future Michael Roukes IN THE late 1950s visionary physicist 1 Feynman's challenge Richard Feynman issued a public chal- lenge by offering $1000 to the first person to create an electrical motor "smaller than 1 /64th of an inch". Much to Feynman's consternation the young man who met this challenge, William McLellan, did so by investing many tedious and painstaking hours building the device by hand using tweezers and a microscope (figure 1). McLellan's motor now sits in a display case at the California Institute of Tech- nology and has long since ceased to spin. Meanwhile, in the field that Feynman hoped to incite, the wheels are turning- (a) Richard Feynman viewing the micromotor built by William McLellan (left) who won the challenge to both figuratively and literally — in many build the first motor smaller than l/64th of an inch, (b) The motor, 3.81 mm wide, photographed under f, university and corporate laboratories, an optical microscope. The huge object above it is the head of a pin. & and even on industrial production lines. Indeed, the field of microelectromechanical systems (MEMS), MEMS at sizes below one micrometre. This stands in stri- which became firmly established in the mid-1980s, has now king contrast to the recent developments in mainstream matured to the point where we can be rather blase about the microelectronics where chips are now mass-produced with mass production of diminutive motors that are hundreds of features as small as 0.18 microns.
    [Show full text]
  • Arxiv:1403.3703V1 [Quant-Ph]
    Thermalization properties at mK temperatures of a nanoscale optomechanical resonator with acoustic-bandgap shield Se´anM. Meenehan,1, ∗ Justin D. Cohen,1, ∗ Simon Gr¨oblacher,1, 2, ∗ Jeff T. Hill,1 Amir H. Safavi-Naeini,1 Markus Aspelmeyer,2 and Oskar Painter1, y 1Institute for Quantum Information and Matter and Thomas J. Watson, Sr., Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA 2Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, A-1090 Wien, Austria (Dated: March 18, 2014) Optical measurements of a nanoscale silicon optomechanical crystal cavity with a mechanical reso- nance frequency of 3:6 GHz are performed at sub-kelvin temperatures. We infer optical-absorption- induced heating and damping of the mechanical resonator from measurements of phonon occu- pancy and motional sideband asymmetry. At the lowest probe power and lowest fridge temperature (Tf = 10 mK), the localized mechanical resonance is found to couple at a rate of γi=2π = 400 Hz 6 (Qm = 9 × 10 ) to a thermal bath of temperature Tb ≈ 270 mK. These measurements indicate that silicon optomechanical crystals cooled to millikelvin temperatures should be suitable for a variety of experiments involving coherent coupling between photons and phonons at the single quanta level. acoustic 0.5 Introduction. - The coupling of a mechanical object's a b c − ωm ωm radiation κi 0.4 motion to the electromagnetic field of a high finesse cav- shield 0.3 R ity forms the basis of various precision measurements [1], 0.2 κ = κe+κi from large-scale gravitational wave detection [2] to mi- 0.1 0 croscale accelerometers [3].
    [Show full text]
  • 2018 March Meeting Program Guide
    MARCHMEETING2018 LOS ANGELES MARCH 5-9 PROGRAM GUIDE #apsmarch aps.org/meetingapp aps.org/meetings/march Senior Editor: Arup Chakraborty Robert T. Haslam Professor of Chemical Engineering; Professor of Chemistry, Physics, and Institute for Medical Engineering and Science, MIT Now welcoming submissions in the Physics of Living Systems Submit your best work at elifesci.org/physics-living-systems Image: D. Bonazzi (CC BY 2.0) Led by Senior Editor Arup Chakraborty, this dedicated new section of the open-access journal eLife welcomes studies in which experimental, theoretical, and computational approaches rooted in the physical sciences are developed and/or applied to provide deep insights into the collective properties and function of multicomponent biological systems and processes. eLife publishes groundbreaking research in the life and biomedical sciences. All decisions are made by working scientists. WELCOME t is a pleasure to welcome you to Los Angeles and to the APS March I Meeting 2018. As has become a tradition, the March Meeting is a spectacular gathering of an enthusiastic group of scientists from diverse organizations and backgrounds who have broad interests in physics. This meeting provides us an opportunity to present exciting new work as well as to learn from others, and to meet up with colleagues and make new friends. While you are here, I encourage you to take every opportunity to experience the amazing science that envelops us at the meeting, and to enjoy the many additional professional and social gatherings offered. Additionally, this is a year for Strategic Planning for APS, when the membership will consider the evolving mission of APS and where we want to go as a society.
    [Show full text]
  • Works of Love
    reader.ad section 9/21/05 12:38 PM Page 2 AMAZING LIGHT: Visions for Discovery AN INTERNATIONAL SYMPOSIUM IN HONOR OF THE 90TH BIRTHDAY YEAR OF CHARLES TOWNES October 6-8, 2005 — University of California, Berkeley Amazing Light Symposium and Gala Celebration c/o Metanexus Institute 3624 Market Street, Suite 301, Philadelphia, PA 19104 215.789.2200, [email protected] www.foundationalquestions.net/townes Saturday, October 8, 2005 We explore. What path to explore is important, as well as what we notice along the path. And there are always unturned stones along even well-trod paths. Discovery awaits those who spot and take the trouble to turn the stones. -- Charles H. Townes Table of Contents Table of Contents.............................................................................................................. 3 Welcome Letter................................................................................................................. 5 Conference Supporters and Organizers ............................................................................ 7 Sponsors.......................................................................................................................... 13 Program Agenda ............................................................................................................. 29 Amazing Light Young Scholars Competition................................................................. 37 Amazing Light Laser Challenge Website Competition.................................................. 41 Foundational
    [Show full text]
  • May 2013 • Vol
    May 2013 • Vol. 22, No. 5 Nominees Sought for Nicholson Medal A PUBLICATION OF THE AMERICAN PHYSICAL SOCIETY page 7 WWW.APS.ORG/PUBLICATIONS/APSNEWS AIP Reorganizes its Publishing Operations Brinkman Looks Back on Good Science and Tough Decisions By Michael Lucibella ily of journals, including Physical William F. Brinkman stepped actor] forward very successfully, science came out of things like In February, the American In- Review Letters, Physical Review down last month as the Director of we moved the free electron laser the biofuel centers and the EFRCs stitute of Physics established a X and Reviews of Modern Physics, the Office of Science in the U.S. to completion and it’s working. [Energy Frontier Research Cen- new wholly owned, but manageri- whereas AIP publishes a portfo- Department of Energy, the leading Those were very important ac- ters] I think they were very inno- ally independent, limited liability lio of 17 journals, many of which funder of physical science in the complishments. NSLS II [Nation- vative and have produced a lot of company to oversee publishing all concentrate on applied areas of federal government. He had held very good science, whether it was of its research journals. The move physics, as well as journals of sev- this post since June of 2009, prior on lignins [an organic compound comes amidst a broader restructur- eral of its member societies. to which he was a Senior Research that could be a renewable fuel ing effort by AIP to modernize its Several APS divisions and Physicist at Princeton, and before source] or on breaking down cel- governance, and better respond to topical groups correspond closely that Vice President for Research at lulose and that kind of thing, but the changing publishing market.
    [Show full text]
  • Patterned Photostimulation Via Visible-Wavelength Photonic Probes for Deep Brain Optogenetics
    Patterned photostimulation via visible-wavelength photonic probes for deep brain optogenetics Eran Segev Jacob Reimer Laurent C. Moreaux Trevor M. Fowler Derrick Chi Wesley D. Sacher Maisie Lo Karl Deisseroth Andreas S. Tolias Andrei Faraon Michael L. Roukes Eran Segev, Jacob Reimer, Laurent C. Moreaux, Trevor M. Fowler, Derrick Chi, Wesley D. Sacher, Maisie Lo, Karl Deisseroth, Andreas S. Tolias, Andrei Faraon, Michael L. Roukes, “Patterned photostimulation via visible-wavelength photonic probes for deep brain optogenetics,” Neurophoton. 4(1), 011002 (2016), doi: 10.1117/1.NPh.4.1.011002. Downloaded From: http://neurophotonics.spiedigitallibrary.org/ on 12/07/2016 Terms of Use: http://spiedigitallibrary.org/ss/termsofuse.aspx Neurophotonics 4(1), 011002 (Jan–Mar 2017) Patterned photostimulation via visible-wavelength photonic probes for deep brain optogenetics Eran Segev,a,b Jacob Reimer,c Laurent C. Moreaux,b Trevor M. Fowler,a,b Derrick Chi,a,b Wesley D. Sacher,a,b Maisie Lo,d Karl Deisseroth,d,e Andreas S. Tolias,c Andrei Faraon,a,f and Michael L. Roukesa,b,* aKavli Nanoscience Institute, California Institute of Technology, Pasadena, California 91125, United States bCalifornia Institute of Technology, Departments of Physics, Applied Physics, and Bioengineering, 1200 East California Boulevard, MC149-33, Pasadena, California 91125, United States cBaylor College of Medicine, Department of Neuroscience, One Baylor Plaza, Suite S553, Houston, Texas 77030, United States dStanford University, Department of Bioengineering, Stanford, West 250, Clark Center, 318 Campus Drive West, California 94305, United States eStanford University, Howard Hughes Medical Institute, Department of Psychiatry and Behavioral Sciences, West 083, Clark Center, 318 Campus Drive West, Stanford, California 94305, United States fCalifornia Institute of Technology, Departments of Applied Physics and Medical Engineering, 1200 East California Boulevard, MC107-81, Pasadena, California 91125, United States Abstract.
    [Show full text]
  • Matthew Lahaye, Ph.D. January 2018 1
    Matthew LaHaye, Ph.D. January 2018 Matthew D. LaHaye, Ph.D. CONTACT Physics Building 209 Phone: 626-660-5108, 315-443-2564 INFORMATION Department of Physics Fax: 315-443-9103 Syracuse University E-mail: [email protected] Syracuse, NY 13244 Website: http://lahayelab.syr.edu EXPERTISE Nanoelectromechanical systems and superconducting devices. Quantum measurement and qubit technology. Design and fabrication (nanofabrication and microfabrication) of solid-state electronic and mechanical systems. Cryogenic (milli-Kelvin) equipment and measurement techniques. Ultra-sensitive low frequency and microwave measurement equipment and practices. EDUCATION University of Maryland, College Park, College Park, MD USA Ph.D. Physics, 2005 Dissertation Title: The Radio Frequency Single-Electron Transistor Displacement Detector Dissertation Advisor: Prof. Keith C. Schwab State University of New York at Albany, Albany, NY USA B.S. Physics (2nd major in Philosophy), 1999 Graduated magna cum laude Phi Beta Kappa inductee, 1997 ACADEMIC 2016-Present Associate Professor, Physics Department, Syracuse POSITIONS University (S.U.) 2009-2016 Assistant Professor, Physics Department, S.U. 2005-2009 Center for Physics of Information (CPI) Postdoctoral Scholar, California Institute of Technology (Caltech) Advisor: Prof. Michael Roukes RESEARCH NSF-DMR Materials World Network: Investigations of Quantum AWARDS 1312421 Fluctuation Relations Using Superconducting Qubits $260,000, 09/15/13-08/31/16 NSF-DMR CAREER: Probing Quantum Behavior in Qubit- 1056423 Coupled Nanomechanical Systems $600,000, 05/15/11-04/30/16 PEER-REVIEWED 8. Rouxinol, F., Hao, Y., Brito, F., Caldeira, A.O., Irish, E.K., & LaHaye PUBLICATIONS M.D. “Measurements of Qubit-Nanoresonator Interactions in a Hybrid Quantum Electromechanical System.” Nanotechnology 27, 364003 (2016).
    [Show full text]
  • Trustees, Administration, Faculty
    Section Six Trustees, Administration, Faculty 546 Trustees, Administration, Faculty OFFICERS Robert B. Chess (2006) Chairman Nektar Therapeutics Kent Kresa, C hairman Lounette M. Dyer (1998) David L. Lee, V ice Chairman Gilad I. Elbaz (2008) Founder Jean-Lou Chameau, President Factual Inc. Edward M. Stolper, Provost William T. Gross (1994) C hairman and Founder Dean W. Currie Idealab V ice President for Business and Frederick J. Hameetman (2006) Finance Chairman Charles Elachi Cal American Vice President and Director, Jet R obert T. Jenkins (2005) Propulsion Laboratory Peter D. Kaufman (2008) Peter D. Hero Chairman and CEO Vice President for Glenair, Inc. Development and Institute Jon Faiz Kayyem (2006) Relations CEO Sharon E. Patterson Osmetech PLC Associate Vice President for Louise Kirkbride (1995) Finance and Treasurer Board Member Scott Richland State of California Contractors Chief Investment Officer State License Board Anneila I. Sargent Jon B. Kutler (2005) Vice President for Student Chairman and CEO Affairs Admiralty Partners, Inc. Victoria D. Stratman Louis J. Lavigne Jr. (2009) General Counsel Management Consultant Mary L. Webster Lavigne Group Secretary David Li Lee (2000) Managing General Partner Clarity Partners, L.P. BOARD OF TRUSTEES York Liao (1997) Managing Director Winbridge Company Ltd. Trustees Alexander Lidow (1998) (with date of first election) CEO EPC Corporation Robert C. Bonner (2008) Ronald K. Linde (1989) Senior Partner Independent Investor Sentinel HS Group, L.L.C. Chair, The Ronald and Maxine Brigitte M. Bren (2009) Linde Foundation John E. Bryson (2005) Founder/Former CEO Chairman and CEO (Retired) Envirodyne Industries, Inc. Edison International Shirley M. Malcom (1999) Jean-Lou Chameau (2006) Director, Education and Human President Resources Programs California Institute of Technology American Association for the Milton Chang (2005) Advancement of Science Managing Director Deborah McWhinney (2007) President Incubic Venture Capital 547 John S.
    [Show full text]
  • Trustees, Administration, Faculty (PDF)
    Section Six Trustees, Administration, Faculty 540 Trustees, Administration, Faculty OFFICERS Robert B. Chess (2006) Chairman Nektar Therapeutics Kent Kresa, Chairman Lounette M. Dyer (1998) David L. Lee, Vice Chairman Gilad I. Elbaz (2008) Founder Jean-Lou Chameau, President Factual Inc. Edward M. Stolper, Provost William T. Gross (1994) Chairman and Founder Dean W. Currie Idealab Vice President for Business and Frederick J. Hameetman (2006) Finance Chairman Charles Elachi Cal American Vice President and Director, Jet Robert T. Jenkins (2005) Propulsion Laboratory Peter D. Kaufman (2008) Sandra Ell Chairman and CEO Chief Investment Officer Glenair, Inc. Peter D. Hero Jon Faiz Kayyem (2006) Vice President for Managing Partner Development and Alumni Efficacy Capital Ltd. Relations Louise Kirkbride (1995) Sharon E. Patterson Board Member Associate Vice President for State of California Contractors Finance and Treasurer State License Board Anneila I. Sargent Kent Kresa (1994) Vice President for Student Chairman Emeritus Affairs Northrop Grumman Corporation Mary L. Webster Jon B. Kutler (2005) Secretary Chairman and CEO Harry M. Yohalem Admiralty Partners, Inc. General Counsel Louis J. Lavigne Jr. (2009) Management Consultant Lavigne Group David Li Lee (2000) BOARD OF TRUSTEES Managing General Partner Clarity Partners, L.P. York Liao (1997) Trustees Managing Director (with date of first election) Winbridge Company Ltd. Alexander Lidow (1998) Robert C. Bonner (2008) CEO Senior Partner EPC Corporation Sentinel HS Group, L.L.C. Ronald K. Linde (1989) Brigitte M. Bren (2009) Independent Investor John E. Bryson (2005) Chair, The Ronald and Maxine Chairman and CEO (Retired) Linde Foundation Edison International Founder/Former CEO Jean-Lou Chameau (2006) Envirodyne Industries, Inc.
    [Show full text]
  • Going the Mile a Megadollar Grant Funds a Nanoscience Institute
    u. 1- 1- u. Cl) 1- The campus community biweekly March 18, 2004, vol. 4, no. 6 Going the mile Rossman receives Revel steps down Feynman Prize as dean George Rossman, professor of mineral­ Dean of Students and Ruddock Professor ogy and the divisional academic officer of Biology Jean-Paul Revel will step for Geological and Planetary Sciences, down from his administrative post in has been awarded the 2003-04 Richard P. June, Vice President for Student Affairs Feynman Prize for Excellence in Teach­ Margo Marshak wrote in a March 8 ing. Acting provost Ed Stolper presented e-mail memo. him with the award at the February 23 Making the announcement "with faculty meeting. great regret," Marshak wrote: "Profes­ The prize committee's recommenda­ sor Revel has provided able and gener­ tion of Rossman reads in part: "George ous leadership as Dean since September Rossman has been teaching with enthusi­ 1996. Over these past years, Professor asm and with superb results since he Revel has made an important difference joined the Caltech faculty in 1971 ... in the lives of our undergraduates for George's style of teaching exploits the whom he has such affection and con­ beautiful and beguiling qualities of miner­ cern. His advice, compassion, and guid­ als and their relationships to geological ance have been invaluable to students processes. He employs a series of mind­ see Revel, page 6 stretching demonstrations .. He tells stories about minerals. He asks probing questions about their color, and then leads students to think in general about the "Bob," the Chevy Tahoe four-wheel drive that was Caltech's entry in Saturday's highly anticipated proper approach to scientific questions.
    [Show full text]
  • Magnetic Microtraps for Cavity QED, Bose-Einstein Condensates, and Atom Optics
    Magnetic Microtraps for Cavity QED, Bose-Einstein Condensates, and Atom Optics Thesis by Benjamin L. Lev In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology Pasadena, California 2006 (Defended September 15, 2005) ii c 2006 Benjamin L. Lev All Rights Reserved iii To my parents, Daniel and Susan iv Acknowledgements One could not ask for a better advisor: throughout my years in graduate school, Hideo Mabuchi has been a friend as well as a mentor. His passion and dedication to science breathes life into research and inspires all who are fortunate enough to work with him. He has not only taught me how to build an experiment, but also, how to think as a scientist. I hope to honor his efforts by carrying his unceasing inquisitiveness wherever I go. In addition to Hideo, I credit Jakob Reichel with encouraging my development as a scientist. Jakob and his wife, Johanna, have been amazingly kind to me over the years, and I am grateful to both Jakob and Professor T. W. H¨ansch for allowing me to participate in their experimental efforts in Munich. Tilo Steinmetz, Philipp Treutlein, Peter Hommelhoff, and Yves Colombe have been wonderful labmates and hosts, and I thank them for teaching me to be a true M¨unchener. I feel fortunate to have been welcomed into Oskar Painter’s lab and appreciate his interest in my research and scientific development. It has been a joy to work with his students, Paul Barclay and Kartik Srinivasan. Hideo has assembled a group of students and colleagues second to none, and I feel privileged to have had the opportunity to work with them: Michael Armen, John Au, Andrew Berglund, Andr´eConjusteau, Andrew Doherty, JM Geremia, Salman Habib, Asa Hopkins, Chungsok Lee, Tim McGarvey, Kevin McHale, Anthony Miller, Benjamin Rahn, Jen Sokol, John Stockton, Ramon Van Handel, and Jon Williams.
    [Show full text]
  • Nanoelectromechanical Systems Continuum Solid: Equations of Motion
    PASI 2006 - Bariloche, Argentina Lectures M.L. Roukes, Caltech NEMS: multiterminal mechanical devices introduction to nano- ELECTRICAL ELECTRICAL input output INPUT mechanical OUTPUT transducer mechanical transducer nanoelectromechanical systems SIGNAL mechanical SIGNAL stimulus system response mechanical perturbation ELECTRICAL control CONTROL transducer SIGNAL mechanical domain Michael Roukes -signal processing Kavli Nanoscience Institute Physics, Applied Physics, & -measurement / sensing Bioengineering -computation California Institute of Technology © 2006 Continuum Solid: Equations of Motion Isotropic solid with local displacement u(r,t) 2 ∂ u 2 ρ = ()()λ + μ ∇ ∇ ⋅u + μ∇ u μ(3λ + 2μ) ∂t 2 Young’s modulus E = Fundamentals: important concepts λ + μ λ, μ are the Lamé constants: λ – beam mechanics (review) λ = c μ = c = (c −c )/2 Poisson ratio ν = 12 44 11 12 2λ + 2μ – responsivity sensitivity –noise – dynamic range Boundary conditions define stress or strain: – nonlinear response Fixed boundary: u(rb ,t) = 0 for rb on boundary Stress-free boundary: T (rb ,t)⋅nˆ = 0 for rb on boundary, n ˆ unit normal Tii = (λ + 2μ)∇ ⋅u nˆ ⎛ ∂u ∂u j ⎞ T = μ⎜ i + ⎟ ij ⎜ ∂r ∂r ⎟ ⎝ j i ⎠ rb see Auld, Acoustic Waves and Fields in Solids (2nd ed.) 1990 © M.L. Roukes 2005 Ph/EE 118c, Ch227 — Micro- and Nanoscale Sensors © 2006 (c) Caltech, 2006 -all rights reserved- Page 1 of 28 1 PASI 2006 - Bariloche, Argentina Lectures M.L. Roukes, Caltech Flexural Beams: Equations of Motion Flexural Beams: Solutions Yn (x,t) = an (cosβn x − coshβn x)+ bn (sin βn x − sinh βn x) Doubly-clamped beam Cantilevered beam Doubly-clamped beam Y(x,t) an ≈ bn (a1 = 1.018b1,a2 = 0.9992b2 ,a3 = 1.000b3 …) Euler-Bernoulli theory: length >> width, thickness … βn L = 4.730, 7.853,10.996 x • Neutral axis displacement Y ωn = E 12ρ βnt • Width w, thickness t (along y) • Density ρ, modulus E = (3λ+2μ)/(λ+μ) Y(x,t) 1234 ∂2Y wt3 ∂4Y x ρwt + E = 0 ∂t 2 12 ∂x4 Boundaries: Clamped end: Y = 0, Y’ = 0 Free end: Y’’ = 0, Y’’’ = 0 See Timoshenko, Vibration Problems in Engineering (1974) © M.L.
    [Show full text]