163 research outputs found
Photon Statistics; Nonlinear Spectroscopy of Single Quantum Systems
A unified description of multitime correlation functions, nonlinear response
functions, and quantum measurements is developed using a common generating
function which allows a direct comparison of their information content. A
general formal expression for photon counting statistics from single quantum
objects is derived in terms of Liouville space correlation functions of the
material system by making a single assumption that spontaneous emission is
described by a master equation
D-concurrence bounds for pair coherent states
The pair coherent state is a state of a two-mode radiation field which is
known as a state with non-Gaussian wave function. In this paper, the upper and
lower bounds for D-concurrence (a new entanglement measure) have been studied
over this state and calculated.Comment: 11 page
Role of electromagnetically induced transparency in resonant four-wave-mixing schemes.
Published versio
Quantum computing implementations with neutral particles
We review quantum information processing with cold neutral particles, that
is, atoms or polar molecules. First, we analyze the best suited degrees of
freedom of these particles for storing quantum information, and then we discuss
both single- and two-qubit gate implementations. We focus our discussion mainly
on collisional quantum gates, which are best suited for atom-chip-like devices,
as well as on gate proposals conceived for optical lattices. Additionally, we
analyze schemes both for cold atoms confined in optical cavities and hybrid
approaches to entanglement generation, and we show how optimal control theory
might be a powerful tool to enhance the speed up of the gate operations as well
as to achieve high fidelities required for fault tolerant quantum computation.Comment: 19 pages, 12 figures; From the issue entitled "Special Issue on
Neutral Particles
Oral Fluid–Based Biomarkers of Alveolar Bone Loss in Periodontitis
Periodontal disease is a bacteria-induced chronic inflammatory disease affecting the soft and hard supporting structures encompassing the teeth. When left untreated, the ultimate outcome is alveolar bone loss and exfoliation of the involved teeth. Traditional periodontal diagnostic methods include assessment of clinical parameters and radiographs. Though efficient, these conventional techniques are inherently limited in that only a historical perspective, not current appraisal, of disease status can be determined. Advances in the use of oral fluids as possible biological samples for objective measures of current disease state, treatment monitoring, and prognostic indicators have boosted saliva and other oral-based fluids to the forefront of technology. Oral fluids contain locally and systemically derived mediators of periodontal disease, including microbial, host-response, and bone-specific resorptive markers. Although most biomarkers in oral fluids represent inflammatory mediators, several specific collagen degradation and bone turnover-related molecules have emerged as possible measures of periodontal disease activity. Pyridinoline cross-linked carboxyterminal telopeptide (ICTP), for example, has been highly correlated with clinical features of the disease and decreases in response to intervention therapies, and has been shown to possess predictive properties for possible future disease activity. One foreseeable benefit of an oral fluid–based periodontal diagnostic would be identification of highly susceptible individuals prior to overt disease. Timely detection and diagnosis of disease may significantly affect the clinical management of periodontal patients by offering earlier, less invasive, and more cost-effective treatment therapies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73247/1/annals.1384.028.pd
Design of a mode converter for efficient light-atom coupling in free space
In this article, we describe how to develop a mode converter that transforms
a plane electromagnetic wave into an inward moving dipole wave. The latter one
is intended to bring a single atom or ion from its ground state to its excited
state by absorption of a single photon wave packet with near-100% efficiency.Comment: RevTex4, 3 figures, revised version, accepted for publication at
Appl. Phys.
Hepatitis C Core-Antigen Testing from Dried Blood Spots
In order to expand hepatitis C virus (HCV) screening, a change in the diagnostic paradigm
is warranted to improve accessibility and decrease costs, such as utilizing dried blood spot (DBS)
collection. In our study, blood from 68 patients with chronic HCV infection was spotted onto DBS cards
and stored at the following temperatures for one week: −80 ◦C, 4 ◦C, 21 ◦C, 37 ◦C, and alternating
37 ◦C and 4 ◦C; to assess whether temperature change during transportation would affect sensitivity.
Sample was eluted from the DBS cards and tested for HCV antibodies (HCV-Ab) and HCV core
antigen (core-Ag). HCV-Abs were detected from 68/68 DBS samples at −80 ◦C, 4 ◦C, 21 ◦C, and 67/68 at
37 ◦C and alternating 37 ◦C and 4 ◦C. Sensitivity of core-Ag was as follows: 94% (−80 ◦C), 94% (4 ◦C),
91% (21 ◦C), 93% (37 ◦C), and 93% (37 ◦C/4
◦C). Not only did temperature not greatly affect sensitivity,
but sensitivities are higher than previously reported, and support the use of this assay as an alternative
to HCV RNA. We then completed a head-to-head comparison (n = 49) of venous versus capillary
samples, and one versus two DBS. No difference in core-Ag sensitivity was observed by sample
type, but there was an improvement when using two spots. We conclude that HCV-Abs and core-Ag
testing from DBS cards has high diagnostic accuracy and could be considered as an alternative to
HCV RNA in certain settings
First cosmology results using SNe Ia from the dark energy survey: analysis, systematic uncertainties, and validation
International audienceWe present the analysis underpinning the measurement of cosmological parameters from 207 spectroscopically classified type Ia supernovae (SNe Ia) from the first three years of the Dark Energy Survey Supernova Program (DES-SN), spanning a redshift range of 0.01
Astronomical Distance Determination in the Space Age: Secondary Distance Indicators
The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)
- …