Speaker: Girish S. Agarwal (Oklahoma State University)

Title: How Much Quantum Noise is Detrimental to Entanglement

I examine the effect of quantum noise on entanglement. The source of noise could be either an attenuator or even an amplifier which one would presumably use in quantum communication protocols. I present quantitative results on the survival of entanglement

as a result of various types of quantum noise. I consider entanglement for both continuous variables [1] and qubits [2].

1. G.S. Agarwal, S. Chaturvedi, arXiv:0906.2743

2. Sumanta Das, G. S. Agarwal arXiv:0901.2114

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Speaker: Ting Yu (Stevens Institute of Technology)

Title: Disentanglement and Control of Qubit Systems

Coherence dynamics of quantum systems is a generic paradigm that has been widely discussed in research fields ranging from atomic and optical physics to condensed matter physics and to quantum information science. In this talk I will present highlights of our recent work on several key issues in entanglement dynamics including evolution of spin entanglement under phonon noise, the sudden death of entanglement, two-body open system entanglement, probing many-body entanglement subject to thermal noise, and entanglement control.

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Speaker: Martin J. Stevens (NIST)

Speaker: Measuring High-Order Coherences of Chaotic and Coherent Optical States

Coauthors: Burm Baek, Eric A. Dauler, Andrew J. Kerman, Richard J. Molnar, Scott A. Hamilton, Karl K. Berggren, Richard P. Mirin and Sae Woo Nam

We demonstrate a new approach to measuring high-order temporal coherences that uses a four-element superconducting nanowire single-photon detector (SNSPD) in which four independent, single-photon-sensitive elements are interleaved over a single spatial mode of the optical beam. We show the power of this technique by measuring nth-order coherences (n = 2,3,4) both of a chaotic, pseudo-thermal source that exhibits high-order photon bunching (up to n!), and of a coherent state source for which all coherences are ~1. Our results demonstrate that using multiple detector elements to parse an optical beam over dimensions smaller than the minimum diffraction-limited spot size can be equivalent-and in some cases superior-to using multiple beamsplitters and discrete detectors that each sample a replica of the entire mode.

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Speaker: Alain Aspect (Groupe d'Optique Atomique)

Title: From Einstein's LichtQuanten to Wheeler's delayed choice experiment: quantum weirdness brought to light.