DOCSLIB.ORG

Abstracts of Monday Posters

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Abstracts of Monday Posters Monday Posters Atom interferometry Mo-001 57 $GLJLWDODWRPLQWHUIHURPHWHUZLWKVLQJOHSDUWLFOHFRQWURO Andrea Alberti 1, *, Andreas Steffen 1, Wolfgang Alt 1, Noomen Belmechri 1, Sebastian Hild 1, 0LFKDá.DUVNL 1, Artur Widera 2,1 and Dieter Meschede 1 ,QVWLWXWIU$QJHZDQGWH3K\VLN8QLYHUVLWlW%RQQ*HUPDQ\ 2. Fachbereich Physik und Forschungszentrum OPTIMAS, Universität Kaiserslautern, Germany *[email protected] Coherent control and delocalization of single trapped atoms constitute powerful new resources for quantum technologies. We will report on a single-atom interferometer that uses spin-dependent periodic potentials to co- herently split and recombine particles with spatial separations of up to 24 lattice sites, equivalent to more than 10 ȝm. The interferometer geometry can be reprogrammed in a digital manner by freely assembling basic coherent operations at discrete time intervals; this allowed us to contrast different geometries and to develop a geometrical- analogue of the well-known spin-echo refocusing. We tested the interferometer by probing external potential gra- dients, achieving with single atoms 5 × 10 –4 precision in units of gravitational acceleration g. Furthermore, a novel scheme for spin-dependent optical lattices is presently underway, with which we expect to reach splitting distances of 1 mm. This coherent control of single-atom wave packets gives us a new way to investigate and exploit interaction effects between atoms; for instance, molecular bound states of two atoms are predicted to occur in quantum walk experiments as a result of matter-wave interference [1]. Reference [1] A. Ahlbrecht, A. Alberti, D. Meschede, V. B. Scholz, A. H. Werner, R. F. Werner, Bound Molecules in an Interacting Quantum :DONDU;LYY Atom interferometry Mo-002 ,QWHUIHURPHWU\ZLWKFKLSEDVHGDWRPODVHUV E. M. Rasel*, for the QUANTUS cooperation QUEST, Institut fr Quantenoptik - Leibniz Universitt, Hannover, Germany *[email protected] We report on the implementation of a Bragg-type interferometer operated with a chip-based atom laser for Rubidium 87 Rb. With the chip based atom laser we can generate thermal ensemble as well as Bose-Einstein conden- sates (BEC) [1]. With the help of delta kick cooling [2], implemented via the atom chip, we can further slow down the expansion of thermal and condensed atoms. In addition, the chip allows to transfer atoms in the individual Zee- PDQVWDWHVRIWKHWZRK\SHU¿QHJURXQGVWDWHVLQSDUWLFXODULQWRWKHQRQPDJQHWLFVWDWH:LWKWKLVWRROER[ZHFRXOG extend the observation of a BEC of only 10000 atoms to macroscopic time scales approaching two seconds. Ben- H¿WLQJIRUPWKHH[WHQGHGIUHHIDOOLQPLFURJUDYLW\ZHFRXOGFRPELQHWKLVZLWKDQDV\PPHWULF0DFK=HKQGHUW\SH interferometer over hundreds of milliseconds to study the coherence and to analyze the delta kick cooling with the help of the observed interference fringes. This experiment can be considered as a double slit experiment in micro- JUDYLW\1%7KH48$1786FRRSHUDWLRQFRPSULVHVWKHJURXSRI&/lPPHU]DKO 8QLY%UHPHQ $:LFKW )%+ $3HWHUV +XPEROGW8QLY%HUOLQ 7+lQVFK-5HLFKHO 034(16 .6HQJVWRFN 8QLY+DPEXUJ 5:DOVHU (TU Darmstadt), and W. P. Schleich (Univ. Ulm). References [1] van Zoest et al. , %RVH(LQVWHLQFRQGHQVDWLRQLQPLFURJUDYLW\ , Science 328, 1540 (2010). [2] H. Amman and N. Christensen, 'HOWD.LFN&RROLQJ$1HZ0HWKRGIRU&RROLQJ$WRPV , Phys. Rev. Lett., 78 , 2088 (1997). 58 Mo-003 Atom interferometry 3UHFLVLRQLQWHUIHURPHWU\ZLWK%RVH(LQVWHLQFRQGHQVDWHV WRZDUGDQHZPHDVXUHPHQWRIWKH¿QHVWUXFWXUHFRQVWDQW Alan O. Jamison 1, *, Ben Plotkin-Swing 1, Anders Hansen 1, Alexander Khramov 1, William Dowd 1, J. Nathan Kutz 1,2, and Subhadeep Gupta 1 'HSWRI3K\VLFV8QLYHUVLW\RI:DVKLQJWRQ6HDWWOH86$ 'HSWRI$SSOLHG0DWKHPDWLFV8QLYHUVLW\RI:DVKLQJWRQ6HDWWOH86$ MDPLVRQD#XZHGX We report progress, both theoretical and experimental, toward an atom interferometric measurement of ƫMYb , IURPZKLFKDYDOXHIRUWKH¿QHVWUXFWXUHFRQVWDQWPD\EHGHWHUPLQHG%\XVLQJDV\PPHWULFWKUHHDUPFRQWUDVW interferometer in free space many potential sources of systematic error cancel. For part per billion precision, such an interferometer requires two of the arms to be coherently accelerated. Experimental progress includes improved DWRPFRROLQJHI¿FLHQF\DOORZLQJSURGXFWLRQRIODUJH aî 5 atom), nearly pure condensates of 174Yb and faster cycle times for a low-momentum prototype interferometer. Theoretical progress includes new techniques for SUHGLFWLQJPHDQ¿HOGHIIHFWVIRUDOOLQWHUDFWLRQVWUHQJWKVLQFOXGLQJWKHLQWHUPHGLDWHVWUHQJWKUHJLPHZKLFKLVNH\ to precision BEC interferometry [1]. These techniques are also valid for waveguide interferometers. A comparison of various coherent acceleration schemes will also be presented. Reference [1] A. O. Jamison, et al. , $WRPLF,QWHUDFWLRQVLQ3UHFLVLRQ,QWHUIHURPHWU\8VLQJ%RVH(LQVWHLQ&RQGHQVDWHV , Phys. Rev. A, 84 , pp. 043643 (2011). Mo-004 Atom interferometry Quantum feedback control of atomic coherent states Ralf Kohlhaas 1, Thomas Vanderbruggen 1, Andrea Bertoldi 1, Simon Bernon 1, Alain Aspect 1, Arnaud Landragin 2, and Philippe Bouyer1,3,* 1. Laboratoire Charles Fabry, Institut d’Optique, CNRS, Université Paris-Sud, Campus Polytechnique, RD 128, 91127 Palaiseau cedex, France 2. LNE-SYRTE, Observatoire de Paris, CNRS and UPMC, 61 avenue de l’Observatoire, F-75014 Paris, France /DERUDWRLUH3KRWRQLTXH1XPpULTXHHW1DQRVFLHQFHV/318QLYHUVLWp%RUGHDX[,2*6&156 805%kW$FRXUVGHODOLEHUDWLRQ7DOHQFH)UDQFH *[email protected] Quantum superposition states are under constant threat to decohere by the interaction with their environment. Active feedback control can protect quantum systems against decoherence, but faces the problem that the measure- ment process itself can change thequantum system. The adaptation of the measurement strategy to a given stabili- zation goal is therefore an essential step to implement quantum feedback control. Here, we present the protection of a collective internal state of an atomic ensemble against a simple decoherence model. A coherent spin state is prepared and exposed to a noise which randomly rotates the state on the Bloch sphere. We use weak nondestruc- WLYHPHDVXUHPHQWVZLWKQHJOLJLEOHSURMHFWLRQRIWKHDWRPLFVWDWHZKLFKVWLOOJLYHVXI¿FLHQWLQIRUPDWLRQWRDSSO\ feedback. This method is used to increase the coherence lifetime of the initial superposition state by about one order of magnitude. Atom interferometry Mo-005 59 $QRYHOFDYLW\EDVHGDWRPLQWHUIHURPHWHU Justin M. Brown1, *, Brian Estey 1, and Holger Müller 1,2 'HSDUWPHQWRI3K\LVFV8QLYHUVLW\RI&DOLIRUQLD%HUNHOH\%HUNHOH\&$86$ /DZUHQFH%HUNHOH\1DWLRQDO/DERUDWRU\2QH&\FORWURQ5RDG%HUNHOH\&$86$ MPEURZQ#EHUNHOH\HGX The world’s leading atom interferometers are housed in bulky atomic fountains. They employ a variety of tech- niques to increase the spatial separation between atomic clouds including high order Bragg diffraction. The largest momentum transfer in a single Bragg beamsplitter has been limited to 24 ƫN by laser power and beam quality [1]. We present an atom interferometer in a 40 cm optical cavity to enhance the available laser power, minimize wave- front distortions, and control other systematic effects symptomatic to atomic fountains. We expect to achieve spatial separations between atomic trajectories comparable to larger scale fountains within a more compact device. We report on progress in developing this new interferometer using cold Cs atoms and discuss its prospects for exploring large momentum transfer up to 100 ƫNLQDVLQJOH%UDJJGLIIUDFWLRQSURFHVV7KHFRPSDFWGHVLJQZLOOHQDEOHWKH¿UVW demonstration of the gravitostatic Aharonov-Bohm effect [2]. References [1] Holger Müller, Sheng-wey Chiow, Quan Long, Sven Herman, and Steven Chu. “Atom Interferometry with up to 24-Photon- Momentum-Transfer Beam Splitters”. Phys. Rev. Lett. 100(18), 180405, (2008). >@0LFKDHO$+RKHQVHH%ULDQ(VWH\3DXO+DPLOWRQ$QWRQ=HLOLQJHUDQG+ROJHU0OOHU³)RUFHIUHHJUDYLWDWLRQDOUHGVKLIWD JUDYLWRVWDWLF$KDUQRQY%RKPH[SHULPHQW´HSULQWDU;LYY Atom interferometry Mo-006 Coherent population transfer of cold 87 5EDWRPVE\ FRXQWHULQWXLWLYHOLJKWSXOVHV Hoon Yu, Mi Hyun Choi, Seung Jin Kim, and Jung Bog Kim 3K\VLFV(GXFDWLRQ.RUHD1DWLRQDO8QLYHUVLW\RI(GXFDWLRQ&KXQJ%XN.RUHDUHSXEOLF We consider counter-intuitive light pulses to transfer atoms coherently from the ground state to another ground VWDWHWKURXJKWKHFRPPRQH[FLWHGVWDWHODPEGDW\SHFRQ¿JXUDWLRQ>@:HLQLWLDOO\SUHSDUHG¿HOGIUHHFROG 87 Rb at- oms in the ground state of 5S ) $QGZHGHWHFWHGWKHÀXRUHVFHQFHE\DWRPVLQDQRWKHUJURXQGVWDWH6 (F=2), to measure amount of transferred atoms. We optimized experimental parameters - width of pulses, power of each pulse, delay time between two pulses, and the two photon detuning- until the effective Rabi frequency of over- ODSSHGDUHDRIWZRSXOVHVFRUUHVSRQGVWRʌZKLFKPHDQVWRWDOWUDQVIHU Reference [1] J. B. Kim, J. Lee, A. S. Choe, and Y. Rhee, “Geometrical representation of coherent-excitation methods using delayed and detuned lasers”, Phys. Rev. A 55, pp. 3819-3825 (1997). 60 Mo-007 Atom interferometry 4XDQWXP5DPVH\LQWHUIHURPHWU\ U. Dorner 1,2 1. Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 2. Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK [email protected] The measurement of atomic transition frequencies with Ramsey interferometry has been established as an im- portant tool, not only for general spectroscopic purposes but also to determine frequency standards on which atomic clocks are based on. Improvements of Ramsey interferometry via quantum effects are therefore highly desirable. Here we present methods for quantum enhanced Ramsey-type interferometry
Load more

Recommended publications
  • Virtual Conference Contents
    Virtual Conference Contents 등록 및 발표장 안내 03 2020 한국물리학회 가을 학술논문발표회 및 05 임시총회 전체일정표 구두발표논문 시간표 13 포스터발표논문 시간표 129 발표자 색인 189 이번 호의 표지는 김요셉 (공동 제1저자), Yong Siah Teo (공동 제1저자), 안대건, 임동길, 조영욱, 정현석, 김윤호 회원의 최근 논문 Universal Compressive Characterization of Quantum Dynamics, Phys. Rev. Lett. 124, 210401 (2020) 에서 모티 브를 채택했다. 이 논문에서는 효율적이고 신뢰할 수 있는 양자 채널 진단을 위한 적응형 압축센싱 방법을 제안하고 이를 실험 으로 시연하였다. 이번 가을학술논문발표회 B11-ap 세션에서 김요셉 회원이 관련 주제에 대해서 발표할 예정(B11.02)이다. 2 등록 및 발표장 안내 (Registration & Conference Room) 1. ‌Epitome Any KPS members can download the pdf files on the KPS homepage. (http://www.kps.or.kr) 2. Membership & Registration Fee Category Fee (KRW) Category Fee (KRW) Fellow/Regular member 130,000 Subscription 1 journal 80,000 Student member 70,000 (Fellow/Regular 2 journals 120,000 Registration Nonmember (general) 300,000 member) Nonmember 150,000 1 journal 40,000 (invited speaker or student) Subscription Fellow 100,000 (Student member) 2 journals 60,000 Membership Regular member 50,000 Student member 20,000 Enrolling fee New member 10,000 3. Virtual Conference Rooms Oral sessions Special sessions Division Poster sessions (Zoom rooms) (Zoom rooms) Particle and Field Physics 01, 02 • General Assembly: 20 Nuclear Physics 03 • KPS Fellow Meeting: 20 Condensed Matter Physics 05, 06, 07, 08 • NPSM Senior Invited Lecture: 20 Applied Physics 09, 10, 11 Virtual Poster rooms • Heavy Ion Accelerator Statistical Physics 12 (Nov. 2~Nov. 6) Complex, RAON: 19 Physics Teaching 13 • Computational science: 20 On-line Plasma Physics 14 • New accelerator: 20 Discussion(mandatory): • KPS-KOFWST Young Optics and Quantum Electonics 15 Nov.
    [Show full text]
  • CLEO Conference
    Executive Ballroom Executive Ballroom Executive Ballroom Executive Ballroom 210A 210B 210C 210D CLEO: QELS-Fundamental Science 08:00–10:00 08:00–10:00 08:00–10:00 08:00–10:00 FM1A • Quantum Engineering FM1B • Relativistic Laser-Plasma FM1C • Hyperbolic and Epsilon- FM1D • PT Symmetry and Presider: Nicholas Peters; Applied Interactions near-zero Materials Related Phenomena Communication Sciences, USA Presider: Sergei Tochitsky; Univ. Presider: Philippe Tassin; Presider: Matthias Heinrich, Univ. of California Los Angeles, USA Chalmers Univ., Sweden of Central Florida, USA FM1A.1 • 08:00 Tutorial FM1B.1 • 08:00 Invited FM1C.1 • 08:00 FM1D.1 • 08:00 Quantum Optomechanics, Markus Aspel- High energy ion acceleration and neutron Wave Propagation in Magnetized Epsilon- Beyond PT-symmetry: SUSY-mediated real meyer1; 1Universitat Wien, Austria. This production using relativistic transparency Near-Zero Metamaterials, Arthur Davoyan1, spectra in complex refractive index land- 1 1 1 tutorial provides an introduction to the cur- in solids, Markus Roth1, Daniel Jung2, Kat- Nader Engheta ; Univ. of Pennsylvania, USA. scapes, Mohammad-Ali Miri , Matthias Hein- 1 1 1 rent state-of-the-art, the challenges and the erina Falk2, Nevzat Guler2, Vincent Bagnoud3, In this work we theoretically study light propa- rich , Demetrios N. Christodoulides ; CREOL prospects of achieving quantum optical con- Stefan Bedacht1, Oliver Deppert1, Matthew gation in magnetized epsilon-near-zero (ENZ) The College of Optics and Photonics, Univ. of trol over nano-, micro- and macro-mechanical J. Devlin2, Andrea Favalli2, Juan Fernandez2, metamaterials. We reveal novel regimes of Central Florida, USA. In the presence of gain devices, i.e. quantum optomechanics.
    [Show full text]
  • Itinerant Spin Dynamics in Structures of Reduced Dimensionality
    Itinerant Spin Dynamics in Structures of Reduced Dimensionality A dissertation presented by Paul Thomas Wenk in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Physics Thesis Committee: Prof. Dr. Stefan Kettemann [thesis advisor] (Jacobs University Bremen, Germany & Pohang University of Science and Technology, South Korea) Prof. Dr. Georges Bouzerar (Institut N´eel, France & Jacobs University Bremen, Germany) Prof. Dr. Ulrich Kleinekath¨ofer (Jacobs University Bremen, Germany) Date of Defense: August, 29 2011 ——————————— Jacobs University Bremen School of Engineering and Science © 2011 - Paul Thomas Wenk All rights reserved. Itinerant Spin Dynamics in Structures of Reduced Dimensionality Abstract In the present thesis results of the study of spin dynamics and quantum trans- port in disordered semiconductor quantum wires with spin-orbit coupling are presented. Starting from basic spin dynamics we derive the dependence of the weak localization cor- rection to the conductance on the strength and the kind of spin-orbit interaction (linear and cubic Dresselhaus, as well as Rashba coupling), the width of the quantum wires as well as the mobility, temperature and Zeeman term. Furthermore, we exploit the connec- tion found between the microscopic picture given by the Cooperon and the spin diffusion equation to extract the spin relaxation rate which shows the same wire dependencies as the weak localization correction. We also show how the result depends on the smoothness and the direction of the transverse confinement of the quantum wires. In this context we have addressed the question concerning long persisting or even persistent spin states in spintronic devices, presenting the corresponding optimal adjustment of spin orbit couplings of different kind and optimal alignment of the wire direction in semiconductor crystals.
    [Show full text]
  • Biographical Sketch of JACEK K
    8/31/15 Biographical Sketch of JACEK K. FURDYNA Office Address: Department of Physics University of Notre Dame Notre Dame, IN 46556 (574).631-6741 Home Address: 51981 Farmington Square Road South Bend, IN 46530 (574).277-5165 Date of Birth: September 6, 1933 Place of Birth: Kamionka Strumilowa, Poland Education: B. S. in Physics (Summa cum Laude), 1955, Loyola University, Chicago, Illinois. Ph.D. in Physics, 1960, Northwestern University, Evanston, Illinois. Thesis: “Microwave Faraday Effect in Silicon and Germanium.” Thesis Advisor: Prof. Sybrand Broersma. Positions Held: 1. Research Associate, Department of Electrical Engineering, Northwestern University (1960-1962). 2. Staff Member, Francis Bitter National Magnet Laboratory, M.I.T. (1962-1966). 3. Associate Professor, Department of Physics, Purdue University (1966-1972). 4. Professor, Department of Physics, Purdue University (1972- 1986). 5. Chairman, Materials Sciences Council, Purdue University (1982-1984). 6. Director, Materials Research Laboratory, Purdue University (1984-1985). 7. Professor, Marquez Chair of Information Theory and Computer Technology, Department of Physics, University of Notre Dame (1987-present). 1 8/31/15 Societies: Fellow of the American Physical Society Fellow of the Institute of Physics (IOP), United Kingdom Fellow, American Association for the Advancement of Science Honors: Doctor of Science Honoris Causa, Warsaw Universtity 2002 Doctor of Science Honoris Causa, Purdue Universtity 2007 Nicholas Coernicus Medal, Polish Academy of Sciences 2009 Special Appointments 1. U. S. National Academy of Sciences Exchange Scholar, Institute of Physics of the Polish Academy of Sciences, Warsaw, Poland (1972-1973). 2. Visiting Scientist, National Research Council of Canada, Ottawa, Canada, (July- December 1981). 3. Program Committee, 29th International Conference on Magnetism and Magnetic Materials, Pittsburgh, November 1983.
    [Show full text]
  • Copyright by Shirin Mozaffari 2017
    Copyright by Shirin Mozaffari 2017 The Dissertation Committee for Shirin Mozaffari certifies that this is the approved version of the following dissertation: Spin-Orbit Interaction and Kondo Scattering at the PrAlO3/SrTiO3 Interface: Effects of Oxygen Content Committee: John T. Markert, Supervisor Alex De Lozanne Alexander A. Demkov Zhen Yao John B. Goodenough Spin-Orbit Interaction and Kondo Scattering at the PrAlO3/SrTiO3 Interface: Effects of Oxygen Content by Shirin Mozaffari DISSERTATION Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY THE UNIVERSITY OF TEXAS AT AUSTIN December 2017 To my family, for their never-ending love and support Acknowledgments First and foremost, I would like to express my deepest gratitude to my advisor and mentor Prof. John T. Markert. I joined his group as a volunteer in 2010 and I was so fascinated by his wealth of knowledge, and the diversity and the profound physics underlying each experiment in his lab, that I stayed there since. His calm attitude toward solving problems, giving the students the freedom to find their own direction as scientists, and motivating them without being a micromanager is admirable. Thanks, Dr. Markert, for giving me the opportunity to work in your lab and learn from you; I have extremely enjoyed being your student, and I will forever be indebted to you. I would like to express my gratitude to Mark Monti, who piqued my interest in oxide thin films early on. Mark was a tremendous mentor in teaching me a lot of skills necessary to run the experiments in the lab.
    [Show full text]
  • CHARGES and EXCITONS in ORGANIC and PERVOSKITE LIGHT EMITTING MATERIALS and DEVICES by JUNWEI XU a Dissertation Submitted To
    CHARGES AND EXCITONS IN ORGANIC AND PERVOSKITE LIGHT EMITTING MATERIALS AND DEVICES BY JUNWEI XU A Dissertation Submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Physics May, 2018 Winston-Salem, North Carolina Approved By: David L. Carroll, Ph.D., Advisor Scott M.Geyer, Ph.D., Chair Martin Gulthold, Ph.D. K. Burak Üçer, Ph.D. Richard T. Williams, Ph.D. Dedication and Acknowledgements Most of all, I would like to thank my advisor, Dr. David Carroll, a talented and passionate scientist who took me into Wake Forest University back in 2013. For that, I am very thankful for the fresh new opportunity he offered that I never thought I would have. During my thesis work, I thank him for appreciating my research strengths and patiently encouraging me to improve in my weaker areas. His strong support of my own ideas and research directions, and confidence in my abilities were benefits not all thesis students enjoy (but should). I am also very much indebted to Dr. Richard Williams, who is very patient and thoughtful to guide me to understand these exciting findings of perovskite materials. My time working on optical measurement in ultrafast laser lab was extremely positive and fun. I also would like to thank the members of my dissertation committee, Dr. Burak Üçer, Dr. Scott Geyer, and Dr. Martin Gulthold, not only for their time and patience, but for their intellectual contributions to my development as an independent researcher.
    [Show full text]
  • Transport and Superconductivity in Spin-Orbit Coupled Electron Systems
    Transport and Superconductivity in Spin-Orbit Coupled Electron Systems by Joel Gordon Hutchinson A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Physics University of Alberta c Joel Gordon Hutchinson, 2019 Abstract This thesis provides a theoretical discussion of several new phenomena associated with spin-orbit coupling in systems that lack inversion symmetry. Chapter 1 gives an in- troduction to the context of spin-orbit coupling in condensed matter physics and the role of inversion symmetry breaking. The remainder of the thesis is divided into two parts. Part 1 explores the effects of spin-orbit coupling on low-energy electron-impurity scattering. First, we study the single-particle scattering problem (Chapters 3 and 4) and find a host of unusual properties at ultra-low energies, including a quantized cross section. Chapter 5 extends these results to transport in a many-body system, where the quantized cross section manifests itself as a quantized conductivity. Part 2 explores the effect of spin-orbit coupling on superconductivity within BCS theory. In Chapter 7, we find that the critical temperature can be tuned by this coupling. In Chapter 8 we discuss the symmetry of the superconducting order parameter in the presence of at- tractive interactions between nearest-neighbour electrons. There we find that the gap function symmetry can change as a function of all the material parameters, including the temperature and spin-orbit coupling. ii Preface Chapters 3, 4, 5, and 7 of this dissertation are an elaboration and summary, with permis- sion, of references [1{5], of which I am the first author.
    [Show full text]
  • Spin Orbit Interaction in Semiconductors J
    UNIVERSIDADE DE SÃO PAULO Instituto de Física de São Carlos Spin orbit interaction in semiconductors J. Carlos Egues Instituto de Física de São Carlos Universidade de São Paulo [email protected] International School of Physics Enrico Fermi: Quantum Spintronics and Related Phenomena Varenna, June 19 2012 Lecture 1 • Motivation • Spin & orbit: an early experiment • Spin-orbit interaction: a simple picture • Sommerfeld model + spin orbit: spin splitting • New experiment: interband s-o coupling (2D) • „Cross-dressed‟ atoms as cool spins (energy scales, Zitterbewegung) • Summary Carlos Egues, Varenna 2012 Some (early) motivation 2012 Conventional electronics: charge plays a fundamental role in devices [integrated circuits: resistors, transistors (billions), etc.] Varenna , Vg Egues Source Drain Carlos Carlos Field Effect Transistor (FET) “spin: factor of 2” (http://www.pbs.org/transistor/science/) „Rashba effect‟ Datta and Das (APL 56, 1990) Emmanuel Rashba Supriyo.Datta Gate FM1 2DEG FM2 (courtesy of Th. Schäpers) Motivation 2012 Spin FET (Semiconductor spintronics, etc.) Varenna , • Most popular proposed spintronic device (Datta and Das ’90); Egues • Coherent electric control of magnetic degrees of freedom; Carlos Carlos • Low energy to rotate/flip spins; faster (?); (Hall & Flatté, APL/2006) • More control & various modes of operation. Logic gates with “dynamic” functions: reprogrammable on the fly; Multifunctional: logic, storage, processing, communication, etc, in a single chip? • Design flexibility (hybrid devices, geometry, etc. etc.) • Quantum effects: coherence? Quantum computation? [Awschalom, Flatte, and Samarth, Sci. Am., 2002 (also Sci. Am. Oct/2004); Awschalom & Flatté Nat. Phys. (2007)] • General: fertile ground for novel spin-dependent phenomena. Interplay of many-body effects (tunability) & quantum confinement; spin-flip mechanisms, spin injection and spin polarized transport, non-local quantum correlations (EPR), etc.
    [Show full text]
  • A Tribute to an Outstanding Physicist Y. Levinson
    Lithuanian Journal of Physics, Vol. 52, No. 2, pp. ii–xvi (2012) © Lietuvos moksl ˛uakademija, 2012 A TRIBUTE TO AN OUTSTANDING PHYSICIST Y. LEVINSON (1932–2008) This issue of our journal is devoted to the memory of Yehoshua (Yoshua) Levinson, an outstanding theoretical physicist whose 80 years anniversary is celebrated this year. Y. Levinson was born in Kaunas, Lithuania, and almost 40 years of his life and the beginning of his scientific career were tightly related to Lithuania. In the sixties, Levinson frequently published his papers (see [1–12]) in our journal. He left an important trace in atomic and solid state physics, especially in the fields related to electronic transport and non-equilibrium phenomena in solids. Along with an impressive contribution to these fields of physics, Y. Levinson is also known as a legendary teacher. Formally, he had about 20 PhD students, but actually much more people acknowledge his influence to their formation as scientists. Maybe this was the reason why preparation of the commemorative issue moved so smoothly. In the beginning of 2011 we wrote a number of letters to Levinson’s students, friends and colleagues trying to find those who would like to participate in our project. We expected some interest, but could not anticipate that so many people, in one way or another, felt obliged to help us – with information and photos, as well as scientific or commemorative contributions. We think that this has something to do with the fact that Levinson himself was open to other scientists and did not count time he spent trying to understand, explain and sometimes solve the problems of his colleagues.
    [Show full text]
  • Hyperfine Interactions and Quantum Information Processing in Quantum
    Hyperfine interactions and quantum information processing in quantum dots A dissertation presented by Jacob Mason Taylor to The Department of Physics in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Physics Harvard University Cambridge, Massachusetts August 2006 c 2006 - Jacob Mason Taylor All rights reserved. Thesis advisor Author Mikhail D. Lukin Jacob Mason Taylor Hyperfine interactions and quantum information processing in quantum dots Abstract This thesis explores the feasibility of using electron spins in semiconductor quan- tum dots as fundamental building blocks for quantum information processing. We start from a general perspective, evaluating the possible limits to operation of such a spin-based system. We show that the coherence properties of electron spins are limited by their inter- action with lattice nuclear spins. We then consider approaches that take advantage of the long coherence and relaxation times of the lattice nuclear spins to mitigate their effect on the electron spin, and show how they could be used as a resource for long-term quantum memory in the solid-state. Next, we develop techniques for experimentally probing electron spin–nuclear spin interactions in quantum dots, and demonstrate the controlled creation and measurement of entangled electron spin states. A new paradigm for quantum information processing in the presence of nuclear spins emerges—one that uses two electron spins to form a single quantum bit. We demonstrate theoretically and experimentally the potential for long-lived quantum memory using this system system, and find improved, specialized approaches to quantum communication and quantum computing using pairs of electron spins.
    [Show full text]
  • Controlling the Surface Band Gap in Topological States of Matter
    Controlling the Surface Band Gap in Topological States of Matter Partha Sarathi Mandal Dissertation zur Erlangung des akademischen Grades "doctor rerum naturalium" (Dr. rer. nat.) in der Wissenschaftsdisziplin Physik kondensierter Materie eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultät Institut für Physik und Astronomie der Universität Potsdam und Helmholtz Zentrum Berlin Potsdam, 29.10.2020 Hauptbetreuer: apl. Prof. Dr. Oliver Rader Gutachter: Prof. Dr. Hans-Joachim Elmers Prof. Dr. Martin Weinelt Contents Abstract 2 1 Motivation 4 2 Topological Phases of Matter 7 2.1 Distinction of Topological Phases of Matter . .8 2.2 Integer Quantum Hall State . .8 2.3 Quantum Spin Hall State and Topological Insulators . 15 2.3.1 3D Z2 Topological Insulator . 19 2.3.2 Symmetry-Protected Topological Phases . 21 2.4 Topological Crystalline Insulators . 21 2.4.1 Topological State with Rotational Symmetry . 22 2.4.2 Topological State with Mirror Symmetry . 25 2.5 Quantum Anomalous Hall State . 27 2.6 Spin Orbit Coupling and Rashba Effect . 30 3 Experimental Techniques 35 3.1 Photoelectron Spectroscopy . 35 3.1.1 Single Electron Picture . 35 3.1.2 Three Step Model . 37 3.2 Many Body Aspects . 41 3.3 Symmetry and Selection Rules . 43 3.4 Dimensionality: Bulk and Surface States . 43 3.5 Instrumentation . 45 3.5.1 Experimental Setup . 45 3.5.2 Light Source: Synchrotron radiation . 46 3.5.3 Sample Preparation for ARPES . 48 4 Topological Crystalline Insulator Phase in Pb1−xSnxSe 50 4.1 Observation of TCI Phase in Pb1−xSnxSe .................... 52 4.1.1 Sample Growth and Structural Characterization .
    [Show full text]
  • Kirill Borisovich Tolpygo: Teacher, Advisor and Scientist
    Kirill Borisovich Tolpygo: Teacher, Advisor and Scientist The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Emmanuel Rashba. 2016. Kirill Borisovich Tolpygo: Teacher, Advisor and Scientist. Low Temperature Physics/Физика низких температур 42 (5): I-V. Published Version http://www.donfti.ru/main/wp-content/uploads/2016/05/2016- FNT.pdf Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:27733691 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP Kirill Borisovich Tolpygo: Teacher, Advisor and Scientist My recollections of Kirill Borisovich go back to the 1946/47 Academic year at the Physics Department of Kiev University. Probably, these are the earliest dates in this special issue of the journal of “Low Temperature Physics” dedicated to Tolpygo’ 100th anniversary. He was a great theorist who shaped the development of theoretical physics in Ukraine, first in Kiev and afterwards in Donetsk, and strongly influenced experimental work. Kirill Borisovich served as our instructor at practices in “Electrodynamics” that were termed “seminars”. They followed and supported the lectures by Solomon Isaakovich Pekar1 on this chapter of theoretical physics. These were the first post-WWII years, the central street of the city Kreshchatik still was in ruins. Our small class, about 24 students, was enrolled in 1944, less than a year after the liberation of the city from Nazis.
    [Show full text]