1,570 research outputs found
Analysis of sorbents and catalysts used during a 90-day manned test
Chemical analysis of organic trace contaminants in simulated space station atmospheres desorbed from molecular sieve, silicon gel, and catalyst bed
Thin film dielectric microstrip kinetic inductance detectors
Microwave Kinetic Inductance Detectors, or MKIDs, are a type of low
temperature detector that exhibit intrinsic frequency domain multiplexing at
microwave frequencies. We present the first theory and measurements on a MKID
based on a microstrip transmission line resonator. A complete characterization
of the dielectric loss and noise properties of these resonators is performed,
and agrees well with the derived theory. A competitive noise equivalent power
of 5 W Hz at 1 Hz has been demonstrated. The
resonators exhibit the highest quality factors known in a microstrip resonator
with a deposited thin film dielectric.Comment: 10 pages, 4 figures, APL accepte
PickCells: A Physically Reconfigurable Cell-composed Touchscreen
Touchscreens are the predominant medium for interactions with digital services; however, their current fixed form factor narrows the scope for rich physical interactions by limiting interaction possibilities to a single, planar surface. In this paper we introduce the concept of PickCells, a fully reconfigurable device concept composed of cells, that breaks the mould of rigid screens and explores a modular system that affords rich sets of tangible interactions and novel acrossdevice relationships. Through a series of co-design activities – involving HCI experts and potential end-users of such systems – we synthesised a design space aimed at inspiring future research, giving researchers and designers a framework in which to explore modular screen interactions. The design space we propose unifies existing works on modular touch surfaces under a general framework and broadens horizons by opening up unexplored spaces providing new interaction possibilities. In this paper, we present the PickCells concept, a design space of modular touch surfaces, and propose a toolkit for quick scenario prototyping
Measurement of the anisotropy power spectrum of the radio synchrotron background
We present the first targeted measurement of the power spectrum of
anisotropies of the radio synchrotron background, at 140 MHz where it is the
overwhelmingly dominant photon background. This measurement is important for
understanding the background level of radio sky brightness, which is dominated
by steep-spectrum synchrotron radiation at frequencies below 0.5 GHz and has
been measured to be significantly higher than that which can be produced by
known classes of extragalactic sources and most models of Galactic halo
emission. We determine the anisotropy power spectrum on scales ranging from 2
degrees to 0.2 arcminutes with LOFAR observations of two 18 square degree
fields -- one centered on the Northern hemisphere coldest patch of radio sky
where the Galactic contribution is smallest and one offset from that location
by 15 degrees. We find that the anisotropy power is higher than that
attributable to the distribution of point sources above 100 micro-Jy in flux.
This level of radio anisotropy power indicates that if it results from point
sources, those sources are likely at low fluxes and incredibly numerous, and
likely clustered in a specific manner.Comment: 8 pages, 5 figures, published in MNRAS, updated to published versio
Computing prime factors with a Josephson phase qubit quantum processor
A quantum processor (QuP) can be used to exploit quantum mechanics to find
the prime factors of composite numbers[1]. Compiled versions of Shor's
algorithm have been demonstrated on ensemble quantum systems[2] and photonic
systems[3-5], however this has yet to be shown using solid state quantum bits
(qubits). Two advantages of superconducting qubit architectures are the use of
conventional microfabrication techniques, which allow straightforward scaling
to large numbers of qubits, and a toolkit of circuit elements that can be used
to engineer a variety of qubit types and interactions[6, 7]. Using a number of
recent qubit control and hardware advances [7-13], here we demonstrate a
nine-quantum-element solid-state QuP and show three experiments to highlight
its capabilities. We begin by characterizing the device with spectroscopy.
Next, we produces coherent interactions between five qubits and verify bi- and
tripartite entanglement via quantum state tomography (QST) [8, 12, 14, 15]. In
the final experiment, we run a three-qubit compiled version of Shor's algorithm
to factor the number 15, and successfully find the prime factors 48% of the
time. Improvements in the superconducting qubit coherence times and more
complex circuits should provide the resources necessary to factor larger
composite numbers and run more intricate quantum algorithms.Comment: 5 pages, 3 figure
Radio Continuum and Star Formation in CO-rich Early Type Galaxies
In this paper we present new high resolution VLA 1.4 GHz radio continuum
observations of five FIR bright CO-rich early-type galaxies and two dwarf
early-type galaxies. The position on the radio-FIR correlation combined with
striking agreements in morphology between high resolution CO and radio maps
show that the radio continuum is associated with star formation in at least
four of the eight galaxies. The average star formation rate for the sample
galaxies detected in radio is approximately 2 solar masses per year. There is
no evidence of a luminous AGN in any of our sample galaxies. We estimate Toomre
Q values and find that the gas disks may well be gravitationally unstable,
consistent with the above evidence for star formation activity. The radio
continuum emission thus corroborates other recent suggestions that star
formation in early type galaxies may not be uncommon.Comment: 21 pages, 7 figures, to be published in the Astronomical Journa
Deterministic entanglement of photons in two superconducting microwave resonators
Quantum entanglement, one of the defining features of quantum mechanics, has
been demonstrated in a variety of nonlinear spin-like systems. Quantum
entanglement in linear systems has proven significantly more challenging, as
the intrinsic energy level degeneracy associated with linearity makes quantum
control more difficult. Here we demonstrate the quantum entanglement of photon
states in two independent linear microwave resonators, creating N-photon NOON
states as a benchmark demonstration. We use a superconducting quantum circuit
that includes Josephson qubits to control and measure the two resonators, and
we completely characterize the entangled states with bipartite Wigner
tomography. These results demonstrate a significant advance in the quantum
control of linear resonators in superconducting circuits.Comment: 11 pages, 11 figures, and 3 tables including supplementary materia
Diffuse Sources, Clustering and the Excess Anisotropy of the Radio Synchrotron Background
We present the largest low frequency (120~MHz) arcminute resolution image of
the radio synchrotron background (RSB) to date, and its corresponding angular
power spectrum of anisotropies (APS) with angular scales ranging from
to . We show that the RSB around the North Celestial Pole has a
significant excess anisotropy power at all scales over a model of unclustered
point sources based on source counts of known source classes. This anisotropy
excess, which does not seem attributable to the diffuse Galactic emission,
could be linked to the surface brightness excess of the RSB. To better
understand the information contained within the measured APS, we model the RSB
varying the brightness distribution, size, and angular clustering of potential
sources. We show that the observed APS could be produced by a population of
faint clustered point sources only if the clustering is extreme and the size of
the Gaussian clusters is . We also show that the observed APS
could be produced by a population of faint diffuse sources with sizes , and this is supported by features present in our image. Both of these
cases would also cause an associated surface brightness excess. These classes
of sources are in a parameter space not well probed by even the deepest radio
surveys to date.Comment: 13 pages, 14 figures. Accepted for publication in MNRA
Generation of Three-Qubit Entangled States using Superconducting Phase Qubits
Entanglement is one of the key resources required for quantum computation, so
experimentally creating and measuring entangled states is of crucial importance
in the various physical implementations of a quantum computer. In
superconducting qubits, two-qubit entangled states have been demonstrated and
used to show violations of Bell's Inequality and to implement simple quantum
algorithms. Unlike the two-qubit case, however, where all maximally-entangled
two-qubit states are equivalent up to local changes of basis, three qubits can
be entangled in two fundamentally different ways, typified by the states
and . Here we demonstrate the operation of three coupled
superconducting phase qubits and use them to create and measure
and states. The states are fully characterized
using quantum state tomography and are shown to satisfy entanglement witnesses,
confirming that they are indeed examples of three-qubit entanglement and are
not separable into mixtures of two-qubit entanglement.Comment: 9 pages, 5 figures. Version 2: added supplementary information and
fixed image distortion in Figure 2
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