2,371 research outputs found
Entanglement Generation of Clifford Quantum Cellular Automata
Clifford quantum cellular automata (CQCAs) are a special kind of quantum
cellular automata (QCAs) that incorporate Clifford group operations for the
time evolution. Despite being classically simulable, they can be used as basic
building blocks for universal quantum computation. This is due to the
connection to translation-invariant stabilizer states and their entanglement
properties. We will give a self-contained introduction to CQCAs and investigate
the generation of entanglement under CQCA action. Furthermore, we will discuss
finite configurations and applications of CQCAs.Comment: to appear in the "DPG spring meeting 2009" special issue of Applied
Physics
Notes on the distribution and breeding of the Manus Friarbird Philemon albitorques and other birds of small islands of the Admiralties Group, Papua New Guinea
Despite being a relatively common and well-known species locally, the ecology of the Manus Friarbird Philemon albitorques is not well documented in the literature. Here I present information on breeding and range extensions for this species, and for other bird species on small islands in the Admiralties Group, Papua New Guinea
Superballistic Diffusion of Entanglement in Disordered Spin Chains
We study the dynamics of a single excitation in an infinite XXZ spin chain,
which is launched from the origin. We study the time evolution of the spread of
entanglement in the spin chain and obtain an expression for the second order
spatial moment of concurrence, about the origin, for both ordered and
disordered chains. In this way, we show that a finite central disordered region
can lead to sustained superballistic growth in the second order spatial moment
of entanglement within the chain.Comment: 5 pages, 1 figur
The Body Drawn Between Knowledge and Desire
The architectural drawing brings together two aspects of architecture’s inescapable relationship with the human body: knowledge and desire. When Adolf Loos designed the never built Josephine Baker House (1928), his drawings mobilized and transmitted knowledge of the human body in general. At the same time, Loos deployed architectural means to express desire for the dancer’s body. The sections and plans suggest that the Viennese architect imagined Baker swimming in a pool whose submerged walls include large windows looking into the watery stage, enveloping the dancer’s body while putting it on display for guests.Considered more generally, the architectural drawing always contains these two bodily moments, insofar as it describes proposals that give form to the lived world. This dynamic couple in the drawing corresponds to the difference between touching the body and grasping it; between an architect pursuing the desire to affect others through their senses and an architectural discipline extending its knowledge of human existence. This article considers relevant aspects in the writings of Robin Evans, Michel Foucault, Michel de Certeau, William T. Mitchell, and Jean-Luc Nancy to develop a theoretical basis for understanding the tensions and alliances at play when architecture draws the body between knowledge and desire
Construction and testing of the optical bench for LISA pathfinder
eLISA is a space mission designed to measure gravitational radiation over a frequency range of 0.1–100 mHz (European Space Agency LISA Assessment Study Report 2011). It uses laser interferometry to measure changes of order in the separation of inertial test masses housed in spacecraft separated by 1 million km. LISA Pathfinder (LPF) is a technology demonstrator mission that will test the key eLISA technologies of inertial test masses monitored by laser interferometry in a drag-free spacecraft. The optical bench that provides the interferometry for LPF must meet a number of stringent requirements: the optical path must be stable at the few level; it must direct the optical beams onto the inertial masses with an accuracy of better than ±25 μm, and it must be robust enough not only to survive launch vibrations but to achieve full performance after launch. In this paper we describe the construction and testing of the flight optical bench for LISA Pathfinder that meets all the design requirements
Precision absolute positional measurement of laser beams
We describe an instrument which, coupled with a suitable coordinate measuring machine, facilitates the absolute measurement within the machine frame of the propagation direction of a millimeter-scale laser beam to an accuracy of around ±4  μm in position and ±20  μrad in angle
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