Bulletin of the American Physical Society
38th Annual Meeting of the Division of Atomic, Molecular, and Optical Physics
Volume 52, Number 7
Tuesday–Saturday, June 5–9, 2007; Calgary, Alberta, Canada
Session G2: Quantum Metrology and Imaging |
Hide Abstracts |
Chair: B. Sanders, University of Calgary Room: TELUS Convention Centre Macleod D |
Thursday, June 7, 2007 8:00AM - 8:36AM |
G2.00001: Multi-Photon Quantum Interferometry Invited Speaker: Based on the investigation of multi-photon entanglement, as produced by stimulated parametric down-conversion, a technique is presented to create heralded ``noon'' states. The relevance for interferometry will be discussed. Furthermore we explored the use of photon-number resolving detectors in Mach-Zehnder type of interferometers. Our current detectors can distinguish 0, 1, 2, to7, photon impacts. Although the overall collection and detection efficiency of photons is well below unity (about 0.3) the photon number resolving property is still very useful if combined with coherent input states since those state are eigenstates of the photon annihilation operator. First we analyze the coherent state interferometer with a single photon-number resolving detector, revealing the strong non-linear response of an interferometer in the case of Fock-state projection. Second, we use two such detectors together with a Baysian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift. This protocol is unbiased and saturates the Cramer-Rao phase uncertainty bound and, therefore, is an optimal phase estimation strategy. As a final topic it will be shown how quantum interferometry combined with micromechanical structures can be used to investigate quantum superpositions and quantum decoherence of macroscopic objects. [Preview Abstract] |
Thursday, June 7, 2007 8:36AM - 9:12AM |
G2.00002: Quantum Imaging: Enhanced Image Formation Using Quantum States of Light Invited Speaker: Image formation based on the use of quantum states of light permits significant new possibilities in the field of image science. In this contribution, we review some of the conceptual possibilities afforded by quantum imaging, and we describe recent work that displays some of these features. The underlying idea of quantum imaging is to implement ideas and techniques from the fields of quantum optics and quantum information science to perform image formation with sensitivity and resolution exceeding that available using classical techniques. Examples of improved image formation includes techniques to form images with resolution exceeding the traditional Rayleigh limit and techniques based on entangled photons to allow the formation of images using photons that have never interacted with the object to be imaged. Quantum imaging systems can also be used to detect weak phase and amplitude objects in the presence of background noise with a sensitivity that exceeds the classical shot-noise limit. Possible long term implications of quantum imaging include its implementation in systems for quantum computing and quantum teleportation, thereby greatly increasing the information capacity by exploiting the parallelism intrinsic to image-bearing optical beams. [Preview Abstract] |
Thursday, June 7, 2007 9:12AM - 9:48AM |
G2.00003: Optical Quantum Imaging, Computing, and Metrology: What's New With N00N States? Invited Speaker: Information science is entering into a new era in which certain subtleties of quantum mechanics enables large enhancements in computational efficiency and communication security. Naturally, precise control of quantum systems required for the implementation of quantum information processing protocols implies potential breakthoughs in other sciences and technologies. We discuss recent developments in quantum control in optical systems and their applications in metrology and imaging. In this context, we particularly focus on novel schemes for the generation, characterization, and detection of N00N and related entangled states of light. [Preview Abstract] |
Thursday, June 7, 2007 9:48AM - 10:24AM |
G2.00004: Mode-mashing and quantum interferometry with triphoton states Invited Speaker: For a number of years, many proposals have observed that the resolution of interferometry could be vastly improved, reaching the ``Heisenberg limit'' of $\Delta \phi \quad \approx $ 1/N, if the particles in the interferometer could be in a maximally entangled state of all travelling one path or the other, $\vert $N,0$>+\vert $0,N$>$, or ``N00N.'' This is a quadratic improvement over the shot-noise limit in classical interferometers, and might lead to significant improvements in metrology, and possibly even lithography. Unfortunately, given the nearly non-interacting nature of photons, such states have proved elusive for N$>$2. Recently, a new theoretical approach based on post-selective nonlinearity has paved the way to scalable generation of such states, which we have generated for N=3. In this talk, I review this approach, our experiment based on what we term ``mode-mashing,'' and their future prospects and limitations. I also discuss the difficult issue of how to perform complete quantum characterisations of such multi-photon states, in which the particles are distinguished only by their polarisations, which are in a complicated entangled state. We have generalized the standard techniques of quantum tomography to take into account the potential presence of extra ``distinguishing'' information inaccessible to measurement, and discuss the resulting limitations on one's ability to fully describe a quantum state. In the limit of completely indistinguishable photons, we argue that the N-photon object should be thought of essentially as a single composite spin-N/2 particle, whose polarisation state may be described by a generalized Wigner quasiprobability distribution over the classical phase space which is the surface of the Poincar\'{e} sphere. We generate a variety of coherent, spin-squeezed, and maximally entangled states, and show the resulting Wigner functions and density matrices. \newline \textbf{References} \newline 1. M.W. Mitchell, J.S. Lundeen, and A.M. Steinberg, Nature \textbf{429}, 161 (2004) \newline 2. R.B.A. Adamson, L.K. Shalm, M.W. Mitchell, and A.M. Steinberg, Phys. Rev. Lett. \textbf{98}, 043601 (2007) \newline 3. R.B.A. Adamson, P.S. Turner, M.W. Mitchell, and A.M. Steinberg, quant-ph/0612081 [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700