1,633 research outputs found
Quantum critical behavior in strongly interacting Rydberg gases
We study the appearance of correlated many-body phenomena in an ensemble of
atoms driven resonantly into a strongly interacting Rydberg state. The ground
state of the Hamiltonian describing the driven system exhibits a second order
quantum phase transition. We derive the critical theory for the quantum phase
transition and show that it describes the properties of the driven Rydberg
system in the saturated regime. We find that the suppression of Rydberg
excitations known as blockade phenomena exhibits an algebraic scaling law with
a universal exponent.Comment: 4 pages, 3 figures, published versio
Cavity-induced temperature control of a two-level system
We consider a two-level atom interacting with a single mode of the
electromagnetic field in a cavity within the Jaynes-Cummings model. Initially,
the atom is thermal while the cavity is in a coherent state. The atom interacts
with the cavity field for a fixed time. After removing the atom from the cavity
and applying a laser pulse the atom will be in a thermal state again. Depending
on the interaction time with the cavity field the final temperature can be
varied over a large range. We discuss how this method can be used to cool the
internal degrees of freedom of atoms and create heat baths suitable for
studying thermodynamics at the nanoscale
Mesoscopic Rydberg Gate based on Electromagnetically Induced Transparency
We demonstrate theoretically a parallelized C-NOT gate which allows to
entangle a mesoscopic ensemble of atoms with a single control atom in a single
step, with high fidelity and on a microsecond timescale. Our scheme relies on
the strong and long-ranged interaction between Rydberg atoms triggering
Electromagnetically Induced Transparency (EIT). By this we can robustly
implement a conditional transfer of all ensemble atoms among two logical
states, depending on the state of the control atom. We outline a many body
interferometer which allows a comparison of two many-body quantum states by
performing a measurement of the control atom.Comment: published versio
Genetic Mechanisms Underlying the Pathogenicity of Cold-Stressed Salmonella Enterica Serovar Typhimurium in Cultured Intestinal Epithelial Cells
Salmonella encounters various stresses in the environment and in the host during infection. The effects of cold (5 C, 48 h), peroxide (5 mM H2O2, 5 h) and acid stress (pH 4.0, 90 min) were tested on pathogenicity of Salmonella. Prior exposure of Salmonella to cold stress significantly (P \u3c 0.05) increased adhesion and invasion of cultured intestinal epithelial (Caco-2) cells. This increased Salmonella-host cell association was also correlated with significant induction of several virulence-associated genes, implying an increased potential of cold-stressed Salmonella to cause an infection. In Caco-2 cells infected with cold-stressed Salmonella, genes involved in the electron transfer chain were significantly induced, but no simultaneous significant increase in expression of antioxidant genes that neutralize the effect of superoxide radicals or reactive oxygen species was observed. Increased production of caspase 9 and caspase 3/7 was confirmed during host cell infection with cold-stressed Salmonella. Further, a prophage gene, STM2699, induced in cold-stressed Salmonella and a spectrin gene, SPTAN1, induced in Salmonella-infected intestinal epithelial cells were found to have a significant contribution in increased adhesion and invasion of cold-stressed Salmonella in epithelial cells
Heat transport in a Coulomb ion crystal with a topological defect
The thermodynamics of low-dimensional systems departs significantly from
phenomenologically deducted macroscopic laws. Particular examples, not yet
fully understood, are provided by the breakdown of Fourier's law and the
ballistic transport of heat. Low-dimensional trapped ion systems provide an
experimentally accessible and well-controlled platform for the study of these
problems. In our work, we study the transport of thermal energy in
low-dimensional trapped ion crystals, focusing in particular on the influence
of the Aubry-like transition that occurs when a topological defect is present
in the crystal. We show that the transition significantly hinders efficient
heat transport, being responsible for the rise of a marked temperature gradient
in the non-equilibrium steady state. Further analysis reveals the importance of
the motional eigenfrequencies of the crystal.Comment: 9 pages, 5 figure
Unique molecular identifier-based high-resolution HLA typing and transcript quantitation using long-read sequencing
HLA typing provides essential results for stem cell and solid organ transplants, as well as providing diagnostic benefits for various rheumatology, gastroenterology, neurology, and infectious diseases. It is becoming increasingly clear that understanding the expression of patient HLA transcripts can provide additional benefits for many of these same patient groups. Our study cohort was evaluated using a long-read RNA sequencing methodology to provide rapid HLA genotyping results and normalized HLA transcript expression. Our assay used NGSEngine to determine the HLA genotyping result and normalized mRNA transcript expression using Athlon2. The assay demonstrated an excellent concordance rate of 99.7%. Similar to previous studies, for the class I loci, patients demonstrated significantly lower expression o
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