Decoherence and Recoherence in Model Quantum Systems

We discuss the various manifestations of quantum decoherence in the forms of dephasing, entanglement with the environment, and revelation of "which-path" information. As a specific example, we consider an electron interference experiment. The coupling of the coherent electrons to the quantized electromagnetic field illustrates all of these versions of decoherence. This decoherence has two equivalent interpretations, in terms of photon emission or in terms of Aharonov-Bohm phase fluctuations. We consider the case when the coherent electrons are coupled to photons in a squeezed vacuum state. The time-averaged result is increased decoherence. However, if only electrons which are emitted during selected periods are counted, the decoherence can be suppressed below the level for the photon vacuum. This is the phenomenon of recoherence. This effect is closely related to the quantum violations of the weak energy condition, and is restricted by similar inequalities. We give some estimates of the magnitude of the recoherence effect and discuss prospects for observing it in an electron interferometry experiment.Comment: 8 pages, 3 figures, talk presented at the 7th Friedmann Seminar, Joao Pessoa, Brazil, July 200

Kerjasama Interpol Dalam Penanganan International Crime Menurut Undang-undang Kepolisian Nomor 2 Tahun 2002

Tujuan dilakukannya penelitian ini adalah untuk mengetahui bagaimana pengaturan kerjasama Interpol menurut Undang-Undang kepolisian nomor 2 tahun 2002 dan bagaimana pelaksanaan kerjasama Interpol menurut Undang-Undang kepolisian nomor 2 tahun 2002. Dengan menggunakan metode penelitian yuridis normative dsimpulkan: 1. Pengaturan kerjasama Interpol menurut Undang-Undang kepolisian nomor 2 tahun 2002 adalah bahwa hubungan dan kerjasama luar negeri dilakukan terutama dengan badan-badan kepolisian dan penegak hukum lain melalui kerjasama bilateral atau multilateral dan badan pencegahan kejahatan baik dalam rangka tugas operasional maupun kerjasama teknik dan pendidikan serta pelatihan. 2. Pelaksanaan kerjasama Interpol menurut Undang-Undang kepolisian nomor 2 tahun 2002 Pasal 42 ayat (4) adalah diatur lebih lanjut dalam peraturan pemerintah yaitu Peraturan Pemerintah Republik Indonesia Nomor 68 Tahun 2008 tentang Tata Cara Pelaksanaan Kerjasama Kepolisian Negara Republik Indonesia yang terkandung dalam 19 Pasal

Polarization conversion spectroscopy of hybrid modes

Enhanced polarization conversion in reflection for the Otto and Kretschmann configurations is introduced as a new method for hybrid-mode spectroscopy. Polarization conversion in reflection appears when hybrid-modes are excited in a guiding structure composed of at least one anisotropic media. In contrast to a dark dip, in this case modes are associated to a peak in the converted reflectance spectrum, increasing the detection sensitivity and avoiding confusion with reflection dips associated with other processes as can be transmission.Comment: 4 pages, 4 figure

Status of Spin Physics - Experimental Summary

The current status of spin physics experiments, based on talks presented at the Third Circum-Pan-Pacific Symposium on High Energy Spin Physics held in Beijing, 2001, is summarized in this article. Highlights of recent experimental results at SLAC, JLab, and DESY, as well as future plans at these facilities and at RHIC-spin are discussed.Comment: 18 pages, 7 figures, Invited talk presented at the Third Circum-Pan-Pacific Symposium on High Energy Spin Physics held in Beijing, October, 200

Rational Approximate Symmetries of KdV Equation

We construct one-parameter deformation of the Dorfman Hamiltonian operator for the Riemann hierarchy using the quasi-Miura transformation from topological field theory. In this way, one can get the approximately rational symmetries of KdV equation and then investigate its bi-Hamiltonian structure.Comment: 14 pages, no figure

Sensitivity-based scaling for correlating structural response from different analytical models

A sensitivity-based linearly varying scale factor is described used to reconcile results from refined models for analysis of the same structure. The improved accuracy of the linear scale factor compared to a constant scale factor as well as the commonly used tangent approximation is demonstrated. A wing box structure is used as an example, with displacements, stresses, and frequencies correlated. The linear scale factor could permit the use of a simplified model in an optimization procedure during preliminary design to approximate the response given by a refined model over a considerable range of design changes