10,910 research outputs found
Dynamics of Quantum Noise in a Tunnel Junction under ac Excitation
We report the first measurement of the \emph{dynamical response} of shot
noise (measured at frequency ) of a tunnel junction to an ac excitation
at frequency . The experiment is performed in the quantum regime,
at very low temperature T=35mK and high
frequency GHz. We observe that the noise responds in phase
with the excitation, but not adiabatically. The results are in very good
agreement with a prediction based on a new current-current correlator.Comment: Theory removed. More experimental details. One extra figur
Regulating Rare Disease: Safely Facilitating Access to Orphan Drugs
While approximately one in ten Americans suffers from a rare disease, only 5 percent of rare diseases have a U.S. Food and Drug Administration (FDA) approved treatment. Congressional and regulatory efforts to stimulate the development of rare-disease treatments, while laudable, have not resolved the fundamental issues surrounding rare-disease treatment development. Indeed, small patient populations, incomplete scientific understanding of rare diseases, and high development costs continually limit the availability of rare-disease treatments. To illustrate the struggle of developing and approving safe rare-disease treatments, this Note begins by discussing the approval of Eteplirsen, the first drug approved for treating a rare disease called Duchenne muscular dystrophy. After exploring the current drug regulation system and how this impacts the availability of rare-disease treatments, this Note examines the 21st Century Cures Act’s patient experience data provisions and the currently pending Trickett Wendler Right to Try Act. Ultimately, the unmet therapeutic needs of rare-disease patients can be met while protecting patient safety, this Note reasons that, if carefully implemented, the 21st Century Cures Act and the Trickett Wendler Right to Try Act could work in tandem to safely facilitate patient access to rare-disease treatments
Magneto-optical Kramers-Kronig analysis
We describe a simple magneto-optical experiment and introduce a
magneto-optical Kramers-Kronig analysis (MOKKA) that together allow extracting
the complex dielectric function for left- and right-handed circular
polarizations in a broad range of frequencies without actually generating
circularly polarized light. The experiment consists of measuring reflectivity
and Kerr rotation, or alternatively transmission and Faraday rotation, at
normal incidence using only standard broadband polarizers without retarders or
quarter-wave plates. In a common case, where the magneto-optical rotation is
small (below 0.2 rad), a fast measurement protocol can be realized,
where the polarizers are fixed at 45 with respect to each other. Apart
from the time-effectiveness, the advantage of this protocol is that it can be
implemented at ultra-high magnetic fields and in other situations, where an
\emph{in-situ} polarizer rotation is difficult. Overall, the proposed technique
can be regarded as a magneto-optical generalization of the conventional
Kramers-Kronig analysis of reflectivity on bulk samples and the Kramers-Kronig
constrained variational analysis of more complex types of spectral data. We
demonstrate the application of this method to the textbook semimetals bismuth
and graphite and also use it to obtain handedness-resolved magneto-absorption
spectra of graphene on SiC.Comment: 11 pages, 4 figur
Environmental, social, morphological, and behavioral constraints on opportunistic multiple paternity
Peer reviewedPostprin
Assessing the performance of protective winter covers for outdoor marble statuary: pilot investigation
Outdoor statuary in gardens and parks in temperate climates has a tradition of being covered during the winter, to protect against external conditions. There has been little scientific study of the environmental protection that different types of covers provide. This paper examines environmental conditions provided by a range of covers used to protect marble statuary at three sites in the UK. The protection required depends upon the condition of the marble. Although statues closely wrapped and with a layer of insulation provide good protection, this needs to be considered against the potential physical damage of close wrapping a fragile deteriorated surface
Optimal molecular alignment and orientation through rotational ladder climbing
We study the control by electromagnetic fields of molecular alignment and
orientation, in a linear, rigid rotor model. With the help of a monotonically
convergent algorithm, we find that the optimal field is in the microwave part
of the spectrum and acts by resonantly exciting the rotation of the molecule
progressively from the ground state, i.e., by rotational ladder climbing. This
mechanism is present not only when maximizing orientation or alignment, but
also when using prescribed target states that simultaneously optimize the
efficiency of orientation/alignment and its duration. The extension of the
optimization method to consider a finite rotational temperature is also
presented.Comment: 14 pages, 12 figure
Decrypting the cyclotron effect in graphite using Kerr rotation spectroscopy
We measure the far-infrared magneto-optical Kerr rotation and reflectivity
spectra in graphite and achieve a highly accurate unified microscopic
description of all data in a broad range of magnetic fields by taking
rigorously the c-axis band dispersion and the trigonal warping into account. We
find that the second- and the forth-order cyclotron harmonics are optically
almost as strong as the fundamental resonance even at high fields. They must
play, therefore, a major role in magneto-optical and magneto-plasmonic
applications based on Bernal stacked graphite and multilayer graphene.Comment: 4 pages, 3 figures + Supplemental Materia
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