************************************ * QUANTUM OPTICS AND ATOM OPTICS * * IN AUSTRALASIA * * * * * * * * MONTHLY NEWSLETTER * * VOL IV, NO 6 * * * CONTENTS: * June 1996 * ________________ * * * ISSN 1325-6467 * 1. ABSTRACTS * * Edited by: Craig Savage 2. CONFERENCES * \ | / * Physics, Faculties, ANU, * \__|__/ * ACT 0200, Australia. * | * email: Craig.Savage@anu.edu.au Available on WWW at: * | * fax: +61 [(0)6] 249 0741 http://www.anu.edu.au * | * voice: +61 [(0)6] 249 4202 /Physics/newsletter * * ___________________ Please send in abstracts for the next newsletter. ___________________ 1. ABSTRACTS ____________ TITLE: Photon Correlation Spectroscopy AUTHORS: H. J. Carmichael [1], P. Kochan [1], B. C. Sanders [2] ADDRESSES: [1] University of Oregon [2] Macquarie University EMAIL: barry@sanders.mpce.mq.edu.au JOURNAL: Physical Review Letters STATUS: Accepted ABSTRACT: A spectroscopic technique for observing excited state resonances in nonperturbative cavity QED is proposed. The feasibility of experiments is demonstrated by a quantum trajectory simulation. ____________ TITLE: EXPERIMENTS IN ATOM OPTICS AUTHORS: Kenneth G.H. Baldwin ADDRESS: Laser Physics Centre, Research School of Physical Sciences and Engineering, Australian National University, Canberra, A.C.T. 0200, Australia EMAIL: Kenneth.Baldwin@anu.edu.au JOURNAL: Australian Journal of Physics STATUS: To be published ABSTRACT: This article outlines experiments which have highlighted the rapid development of the field of atom optics since the mid 1980's. The distinguishing features of the components used in atom optics are compared with their conceptual analogues in light optics. The potential for atom optic devices, both demonstrated and predicted, are described. Experiments and applications of this new technology are reviewed, and the article concludes with a synopsis of work in this field currently being undertaken in Australasia. ____________ TITLE: Measurements on trapped laser-cooled ions using quantum computations. AUTHORS: C. D'Helon and G.J.Milburn ADDRESS: Department of Physics University of Queensland St Lucia 4072 Australia EMAIL: milburn@physics.uq.oz.au JOURNAL: Phys Rev A. STATUS: submitted ABSTRACT: We show that a series of quantum computations involving an isolated N-qubit ion register can be used to make an approximate quantum non-demolition measurement of the number state distribution of the collective vibrational mode. A unitary transformation is applied to the Fourier transformed state of the ion register to copy the vibrational statistics to the electronic mode, and the number state distribution is then measured in the electronic number state basis. ------- TITLE: Optimal phase estimation using active interferometers. AUTHORS: G. J.Milburn, B. C. Sanders and Zhongxi Zhang EMAIL: milburn@physics.uq.oz.au JOURNAL: Phys Rev Lett STATUS: submitted ABSTRACT: We show that phase estimation in an active interferometer (a device which employs nonlinear optical elements) can yield a phase uncertainty which scales inversely with mean photon number. In contrast to optimal phase measurements in passive interferometry, which require exotic nonclassical input states, the scaling for active interferometers is achieved for classical input states. ------- TITLE: Quantum dynamics of an atomic Bose-Einstein condensate in a double-well potential AUTHORS: G. J. Milburn Department of Physics, The University of Queensland, E. M. Wright Department of Physics and Applied Physics, University of Strathclyde, Glasgow, G4 0NG, Scotland, UK D. F. Walls Department of Physics, University of Auckland, Auckland, New Zealand EMAIL: milburn@physics.uq.oz.au JOURNAL: Phys Rev Lett STATUS: submitted ABSTRACT: We consider the quantum dynamics of a neutral atom Bose-Einstein condensate in a double-well potential, including hard-sphere particle interactions. Using a mean-field factorisation we show that the coherent oscillations due to tunnelling are suppressed when the number of atoms exceeds a critical value. An exact quantum solution, in a two-mode approximation, shows that the mean-field solution is modulated by a quantum collapse and revival sequence. -------- TITLE: The Effect of Noise and Modulation on the Reflection of Atoms from an Evanescent Wave. AUTHORS: Wen-Yu Chen, G.J. Milburn and S. Dyrting ADDRESS: Department of Physics, University of Queensland, Brisbane Qld 4072 EMAIL: milburn@physics.uq.oz.au JOURNAL: Phys Rev A STATUS: in press ABSTRACT: We consider the reflection of cold atoms from a temporally modulated evanescent wave, with laser intensity noise, including stochastic surface adsorption. The stochastic surface adsorption is explicitly modelled by means of quantum trajectories while the effect of noise is modelled using the method of stochastic Hamiltonians. The results show that noise destroys quantum features such as interference and splitting, which is especially rapid for semiclassical states. For small noise, modulation can still produce a splitting of the atomic beam, with added dispersion resulting from heating of atoms. In order to distinguish the quantum features, a classical analysis is also presented. &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& 2. CONFERENCES ________________ Quantum Optics Meeting - Satellite Meeting to IQEC '96 8-9 July 1996 Novotel Palm Cove Resort, Cairns, North Queensland, Australia This two-day meeting on Quantum Optics will be a satellite meeting to IQEC'96. It will take place at Novotel Palm Cove Resort, Cairns, North Queensland on Monday 8 and Tuesday 9 July, in the week before the IQEC Meeting in Sydney (14-19 July). The meeting will overlap with the three-day meeting on Atom Optics to be held at the same venue on Tuesday 9, Wednesday 10 and Thursday 11 July. For more details (including registration form) see http://www.physics.uq.oz.au:8001/conference/welcome.html ________________ Atom Optics Meeting- Satellite Meeting to IQEC '96 9-11 July 1996 Novotel Palm Cove Resort, Cairns, North Queensland, Australia This three-day workshop on Atoms Optics and Interferometry will be a satellite meeting to IQEC `96. The workshop will overlap with the two-day workshop on Quantum Optics to be held at the same venue on Monday 8, and Tuesday 9 July. For more details see: http://www.anu.edu.au/Physics/Cairns96/ &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&