2,088 research outputs found
Manufacturing checkout of orbital operational stages Midterm report, period ending 24 Feb. 1965
Manufacturing checkout of orbital operational Saturn S-IVB stage and instrument unit for parking orbit operation
Remote detection of aerosol pollution by ERTS
Photogrammetric and densitometric examination of ERTS-1 MSS imagery of Eastern Virginia coupled with extensive ground truth air quality and meteorological data has shown that the identification and surveying of fixed particulate emitters (smoke plumes) is feasible. A description of the ground truth network is included. The quantitative monitoring of smoke stacks from orbital altitudes over state size regions appears possible when tied to realistic plume models and minimal ground truth. Contrast reductions over urban areas can possibly be utilized to produce isopleths of particulates when supplemented by local measurements
Quantum Heating of a nonlinear resonator probed by a superconducting qubit
We measure the quantum fluctuations of a pumped nonlinear resonator, using a
superconducting artificial atom as an in-situ probe. The qubit excitation
spectrum gives access to the frequency and temperature of the intracavity field
fluctuations. These are found to be in agreement with theoretical predictions;
in particular we experimentally observe the phenomenon of quantum heating
Silicon materials task of the low cost solar array project. Phase 3: Effect of impurities and processing on silicon solar cells
The 13th quarterly report of a study entitled an Investigation of the Effects of Impurities and Processing on Silicon Solar Cells is given. The objective of the program is to define the effects of impurities, various thermochemical processes and any impurity-process interactions on the performance of terrestrial silicon solar cells. The Phase 3 program effort falls in five areas: (1) cell processing studies; (2) completion of the data base and impurity-performance modeling for n-base cells; (3) extension of p-base studies to include contaminants likely to be introduced during silicon production, refining or crystal growth; (4) anisotropy effects; and (5) a preliminary study of the permanence of impurity effects in silicon solar cells. The quarterly activities for this report focus on tasks (1), (3) and (4)
The role of memory in distinguishing risky decisions from experience and description
People’s risk preferences differ for choices based on described probabilities versus those based on information learned through experience. For decisions from description, people are typically more risk averse for gains than for losses. In contrast, for decisions from experience, people are sometimes more risk seeking for gains than losses, especially for choices with the possibility of extreme outcomes (big wins or big losses), which are systematically overweighed in memory. Using a within-subject design, this study evaluated whether this memory bias plays a role in the differences in risky choice between description and experience. As in previous studies, people were more risk seeking for losses than for gains in description but showed the opposite pattern in experience. People also more readily remembered the extreme outcomes and judged them as having occurred more frequently. These memory biases correlated with risk preferences in decisions from experience but not in decisions from description. These results suggest that systematic memory biases may be responsible for some of the differences in risk preference across description and experience
Circuit QED with a Nonlinear Resonator : ac-Stark Shift and Dephasing
We have performed spectroscopic measurements of a superconducting qubit
dispersively coupled to a nonlinear resonator driven by a pump microwave field.
Measurements of the qubit frequency shift provide a sensitive probe of the
intracavity field, yielding a precise characterization of the resonator
nonlinearity. The qubit linewidth has a complex dependence on the pump
frequency and amplitude, which is correlated with the gain of the nonlinear
resonator operated as a small-signal amplifier. The corresponding dephasing
rate is found to be close to the quantum limit in the low-gain limit of the
amplifier.Comment: Paper : 4 pages, 3 figures; Supplementary material : 1 page, 1 figur
Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
In a Rabi oscillation experiment with a superconducting qubit we show that a
visibility in the qubit excited state population of more than 90 % can be
attained. We perform a dispersive measurement of the qubit state by coupling
the qubit non-resonantly to a transmission line resonator and probing the
resonator transmission spectrum. The measurement process is well characterized
and quantitatively understood. The qubit coherence time is determined to be
larger than 500 ns in a measurement of Ramsey fringes.Comment: 4 pages, 5 figures, version with high resolution figures available at
http://www.eng.yale.edu/rslab/Andreas/content/science/PubsPapers.htm
Comment on `Vacuum Rabi Splitting in a Semiconductor Circuit QED System' by Toida et al., Phys. Rev. Lett. 110, 066802 - Published 6 February 2013
Toida et al. claim in their recent article [Phys. Rev. Lett. 110, 066802
(2013)] that they `report a direct observation of vacuum Rabi splitting in a
GaAs/AlGaAs double quantum dot (DQD) based charge qubit coupled with a
superconducting coplanar waveguide (CPW) resonator'. In this comment, we
challenge the main claims made in their paper and show that their results: a)
do not provide any evidence of vacuum Rabi oscillations and b) do not provide
any direct evidence of vacuum Rabi splitting.Comment: 2 pages, 2 figure
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