2,475 research outputs found
A review of type Ia supernova spectra
SN 2011fe was the nearest and best-observed type Ia supernova in a
generation, and brought previous incomplete datasets into sharp contrast with
the detailed new data. In retrospect, documenting spectroscopic behaviors of
type Ia supernovae has been more often limited by sparse and incomplete
temporal sampling than by consequences of signal-to-noise ratios, telluric
features, or small sample sizes. As a result, type Ia supernovae have been
primarily studied insofar as parameters discretized by relative epochs and
incomplete temporal snapshots near maximum light. Here we discuss a necessary
next step toward consistently modeling and directly measuring spectroscopic
observables of type Ia supernova spectra. In addition, we analyze current
spectroscopic data in the parameter space defined by empirical metrics, which
will be relevant even after progenitors are observed and detailed models are
refined.Comment: 58 pages, 15 figures, 6 tables, accepted for publication in Ap&SS as
an invited revie
Spin Readout and Initialization in a Semiconductor Quantum Dot
Electron spin qubits in semiconductors are attractive from the viewpoint of
long coherence times. However, single spin measurement is challenging. Several
promising schemes incorporate ancillary tunnel couplings that may provide
unwanted channels for decoherence. Here, we propose a novel spin-charge
transduction scheme, converting spin information to orbital information within
a single quantum dot by microwave excitation. The same quantum dot can be used
for rapid initialization, gating, and readout. We present detailed modeling of
such a device in silicon to confirm its feasibility.Comment: Published versio
Physiological Arousal and Self-Reported Valence for Erotica Images Correlate with Sexual Policy Preferences
Individuals do not always accurately report the forces driving their policy preferences. Such inaccuracy may result from the fact that true justifications are socially undesirable or less persuasive than competing justifications or are unavailable in conscious awareness. Because of the delicate nature of these issues, people may be particularly likely to misstate the reasons for preferences on gay marriage, abortion, abstinence-only education, and premarital sex. Advocates on both sides typically justify their preferences in terms of preserving social order, maintaining moral values, or protecting civil liberties, not in terms of their own sexual preferences. Though these are the stated reasons, in empirical tests we find that psychophysiological response to sexual images also may be a significant driver of policy attitudes.This work was supported by the National Science Foundation [BCS-0826828]
Identifying single electron charge sensor events using wavelet edge detection
The operation of solid-state qubits often relies on single-shot readout using
a nanoelectronic charge sensor, and the detection of events in a noisy sensor
signal is crucial for high fidelity readout of such qubits. The most common
detection scheme, comparing the signal to a threshold value, is accurate at low
noise levels but is not robust to low-frequency noise and signal drift. We
describe an alternative method for identifying charge sensor events using
wavelet edge detection. The technique is convenient to use and we show that,
with realistic signals and a single tunable parameter, wavelet detection can
outperform thresholding and is significantly more tolerant to 1/f and
low-frequency noise.Comment: 11 pages, 4 figure
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