************************************ * QUANTUM OPTICS AND ATOM OPTICS * * IN AUSTRALASIA * * * * * * * * MONTHLY NEWSLETTER * * VOL VIII, NO 3 * * * * March 2000 * * * * ISSN 1325-6467 * * * Edited by: Bill Munro * \ | / * Physics, University of Queensland, * \__|__/ * QLD 4072, Australia. * | * email: billm@physics.uq.edu.au * | * phone: +61 7 3365 2422 * | * fax: +61 7 3365 1242 Available on WWW at: http://www.physics.uq.edu.au/people/billm/qo.html ------------------------------------------------------------------------------ CONTENTS 0. PROBLEMS 1. ABSTRACTS 2. CONFERENCE ANNOUNCEMENTS 3. WANTED TO BUY/SELL 4. SITUATIONS VACANT 5. MISC NEWS ******************************************************************************* 0. EDITORIAL NOTE Welcome to the third newsletter. Sorry for its late delivery ******************************************************************************* 1. ABSTRACTS Title: Preparing Pure Photon Number States of the Radiation Field Authors: B. T. H. Varcoe[a], S. Brattke[a,b], M. Weidinger[c] and H. Walther[a,b] [a] Max Planck Institute for Quantum Optics Hans-Kopfermann Str. 1, D-85748 Garching, Germany [b] Sektion Physik der UniversitŠt Mźnchen, 85748 Garching, Germany [c] Moved to industry. Ref: Nature 403: (6771), 743-746 February (2000) Abstract: The quantum mechanical description of a radiation field is based on states that are characterised by the number of photon in a particular mode; the most basic quantum states are those with fixed photon number, usually referred to an number or Fock states. Although Fock states of vibrational motion can be readily observed in ion traps[1], Fock states of the radiation field are very fragile and very difficult to produce and maintain. Single photons in multimode fields have been generated using the technique of photon pairs [2,3]. But in order to generate these states in a cavity, the mode in question must have minimal losses; moreover additional sources of photon number fluctuations, such as the thermal field, must be eliminated. Here we observe the build up of number states in a high-Q cavity, by investigating the interaction dynamics of a probe atom with the field. We employ a dynamical method of number state preparation that involves state reduction of highly excited atoms in a cavity, with a photon lifetime as high as 0.2 seconds. (This set-up is usually known as the one atom maser or 'micromaser'.) Pure states containing up to two photons are meausred unambiguously. _____________________________________________ Title: Information Transfer and Fidelity in Quantum Copiers Authors: P. Deuar and W. J. Munro Address: Centre for Laser Science,Department of Physics, University of Queensland, QLD 4072, Brisbane, Australia ref: To appear in PRA Abstract: We find that very different quantum copying machines are optimal depending on the indicator used to assess their performance. Several quantum copying machine models acting on non-orthogonal input states are investigated, and assessed according to two types of criteria: Transfer of (Shannon) information encoded in the initial states to the copies, and fidelity between the copies and the initial states. Transformations which optimise information transfer for messages encoded in qubits are found. If the message is decoded one symbol at a time, information is best copied by a Wootters-Zurek copier. ******************************************************************************* 2. CONFERENCES / WORKSHOPS ***************************************************************************** 4. SITUATIONS VACANT POSTDOCTORAL RESEARCH ASSOCIATE POSITIONS AND PHD SCHOLARSHIPS Centre For Quantum Computer Technology , Australia (Academic) The Australian Centre for Quantum Computer (see article in PHYSICS WORLD, January 2000 p.9) undertakes research on the physics and technology of building, at the atomic level, a solid state quantum computer in silicon. Established in January 2000 through funds from the Australian Research Council and participating institutions, the Centre has nodes at the University of New South Wales, University of Queensland and University of Melbourne, and maintains a substantive collaboration with Los Alamos National Laboratory (USA). The Centre encompasses major research infrastructure including an extensive semiconductor nanofabrication facility, ion implantation, crystal growth, surface analysis and laser physics. 6 POSTDOCTORAL RESEARCH ASSOCIATE (PDRA) POSITIONS - Fixed Term 2-3 years. PDRA - SCANNING TUNNELING MICROSCOPY (Located at UNSW) We seek an experienced PDRA with a strong background in UHV STM. Knowledge of the atomic imaging of silicon surfaces and in particular STM lithography is highly desirable. PDRA - SCANNING PROBE MICROSCOPY (Located at Univ.of Melbourne) We seek a motivated individual with a strong background in scanning probe microscopy and AFM for atomic scale imaging. UHV surface science experience will be highly regarded. PDRA - SILICON MOLECULAR BEAM EPITAXIAL GROWTH (Located at UNSW) We seek a recent physics/engineering PhD or PDRA with a background in semiconductor crystal growth. Experience is desirable in one or more of: UHv, MBE in Si and/or GaAs. PDRA - SEMICONDUCTOR NANOFABRICATION & MEASUREMENT (Located at UNSW) We seek a recent physics/engineering PhD with a background in nanostructure fabrication and measurement. Experience in EBL and/or single electron transistors is highly desirable. PDRA - ION IMPLANTATION (Located at Univ of Melbourne) We seek a motivated individual with experience in high energy (MeV) and low energy (keV) ion implantation doping. Experience in single ion machining & FIB technology is desirable. PDRA - QUANTUM COMPUTAION THEORY (Located at Univ. of Melbourne) We seek a motivated individual to work closely with experimentalists on theory underpinning solid state quantum computation. Areas include: decoherence and error correction, quantum information theory, mesoscopic physics, NMR quantum computing and quantum algorithms. PHD SCHOLARSHIPS 7 Positions - 3 at UNSW; 2 at Univ. Queensland; 2 at Univ. Melbourne Scholarships covering both University fees and living expenses are available for Australian and International candidates. Further details can be found at the website listed below. Closing date for PDRA's: 30 April 2000 Closing date for PhDs: Until Filled. Contact details :For salary levels, position descriptions, selection criteria and application procedure, see our web-site; www.snf.unsw.edu.au or email. Centre Secretariat: email renata.jones@unsw.edu.au ****************************************************************************** 5. MISC NEWS