Generalized qudit Choi maps

Following the linear programming prescription of Ref. \cite{PRA72}, the $d\otimes d$ Bell diagonal entanglement witnesses are provided. By using Jamiolkowski isomorphism, it is shown that the corresponding positive maps are the generalized qudit Choi maps. Also by manipulating particular $d\otimes d$ Bell diagonal separable states and constructing corresponding bound entangled states, it is shown that thus obtained $d\otimes d$ BDEW's (consequently qudit Choi maps) are non-decomposable in certain range of their parameters.Comment: 22 page

Voicing Back: The Poetics and Politics of Ping Chong's Ethno-Historiographic Fables

In spite of Ping Chong¡¯s reputation in the American theatre scene, little has been done to explore his artistic works from a fully theorized perspective. In this dissertation, I propose a category of ¡°cultural narrative texts¡± to investigate cultural and historical themes of ¡°culture and the other¡± in Chong¡¯s fascinating ethno-historiographic fables. The poetics and politics of Chong¡¯s narrative texts are the subject of this dissertation. The frames of myth and narratology in their constructive aspects (how the mythic narratives are expressed) provide the poetics part. I adopt the literary approaches of Northrop Frye and Kenneth Burke for their intense studies on image (narrative unit), rhetoric (narrative signification), and emplotment (narrative sequence). In a connective linkage from poetics, the politics part engages the cultural and historical thematics through which I read what is expressed in Chong¡¯s (counter-) myths on people, cultures, and histories. For this complex thematic part, I construe a theoretical bricolage of a broad range of disciplines and methodologies, from psychoanalysis, cognitive science, anthropology, historiography, sociology, to poststructuralism, postcolonialism, and feminism.This dissertation deals with Chong¡¯s ethno-historiographic fables throughout his theatrical career over three decades, examining how his deconstructive myth-making wrestles with the problematic notion of ¡°the other¡± in both local (national) and global aspects. Borrowing Julia Kristeva¡¯s socially informed psychoanalysis, I approach Chong¡¯s concept of ¡°the other¡± as ¡°social abject¡± inhibiting at the margins. I argue that through Chong¡¯s (counter-) myth-making which destabilizes the authority of hegemonic narratives of the incompatible split between the self and the other, multiple voices of the marginalized return, and the monologue of the hegemonic culture is interrupted. In this dissertation, I demonstrate how the performance of Chong¡¯s (counter-) narratives, what I call ¡°voicing back,¡± resist the silence, enabling the marginalized abject to become the subjects of their own desires and histories. This ¡°voicing back¡± in its shared political languages of respect, equality, and justice (toward the others) prepares for the performance of a democracy which is based on the complete modes of speech acts, speaking and listening

Bloch oscillations and mean-field effects of Bose-Einstein condensates in 1-D optical lattices

We have loaded Bose-Einstein condensates into one-dimensional, off-resonant optical lattices and accelerated them by chirping the frequency difference between the two lattice beams. For small values of the lattice well-depth, Bloch oscillations were observed. Reducing the potential depth further, Landau-Zener tunneling out of the lowest lattice band, leading to a breakdown of the oscillations, was also studied and used as a probe for the effective potential resulting from mean-field interactions as predicted by Choi and Niu [Phys. Rev. Lett. {\bf 82}, 2022 (1999)]. The effective potential was measured for various condensate densities and trap geometries, yielding good qualitative agreement with theoretical calculations.Comment: 5 pages, 3 figures; accepted for publication in Physical Review Letter

Comment on ``Large Slip of Aqueous Liquid Flow over a Nanoengineered Superhydrophobic Surface'' by C-H Choi and C Kim

In a recent Letter (Phys. Rev. Lett. vol 96, 066001 (2006), ref [1]), Choi and Kim reported slip lengths of a few tens of microns for water on nanoengineered superhydrophobic surfaces, on the basis of rheometry (cone-and-plate) measurements. We show that the experimental uncertainty in the experiment of Ref. [1], expressed in term of slip lengths, lies in the range 20 - 100 micrometers, which is precisely the order of magnitude of the reported slip lengths. Moreover we point out a systematic bias expected on the superhydrophobic surfaces. We thus infer that it is not possible to draw out any conclusion concerning the existence of huge slip lengths in the system studied by Choi and Kim.Comment: to appear in Physical Review Letter

Numerical and analytical research of the impact of decoherence on quantum circuits

Three different levels of noisy quantum schemes modeling are considered: vectors, density matrices and Choi-Jamiolkowski related states. The implementations for personal computers and supercomputers are described, and the corresponding results are shown. For the level of density matrices, we present the technique of the fixed rank approximation and show some analytical estimates of the fidelity level.Comment: 11 pages, 9 figures, report for the International Symposium "Quantum Informatics-2014" (QI-2014), Zvenigorod, Moscow region, October 06-10, 201

Ballistic conductance of Ni nanowire with a magnetization reversal

The approach proposed by Choi and Ihm for calculating the ballistic conductance of open quantum systems is generalized to deal with magnetic transition metals. The method has been implemented with ultrasoft pseudopotentials and plane wave basis set in a DFT-LSDA ab-initio scheme. We present the quantum-mechanical conductance calculations for monatomic Ni nanowire with a single spin reversal. We find that a spin reversal blocks the conductance of $d$ electrons at the Fermi energy of the Ni nanowire. On the other hand, two $s$ electrons (one per each spin) are perfectly transmitted in the whole energy window giving $2G_0$ for the total conductance. The relevance of these results in connection with recent experimental data is discussed.Comment: 4 pages, 1 figure, to be published in Surface Scienc

Editorial

In this issue of Literacy and Numeracy Studies, Theres Bellander and Zoe Nikolaidou examine the online health literacy practices of parents whose child or unborn foetus has been diagnosed with a heart defect, and Julie Choi and Ulrike Najar report on their study of the authors’ English language teaching of immigrant and refugee women in Australia